DPF2015

4 Aug 2015, 07:00 → 8 Aug 2015, 17:00 America/Detroit

Dan Levin (University of Michigan (US)), Monica Tecchio (University of Michigan)

 

  Hosted by the University of Michigan Department of Physics

 

 

DPF2015 Proceedings

 

 

Special Guest Lecture

              

    

We are planning five mornings of plenary sessions and four afternoons of parallel sessions. Topics include:

• LHC Run 2 Startup
• Physics Beyond the Standard Model
• Accelerators, Detectors, Computing
• Cosmic Ray Particle Astrophysics
• Cosmology & Dark Matter
• Electroweak & Top Quark
• Field & String Theory
• Outreach & Education
• Flavor Physics
• CP Violation
• Higgs Sector
• Heavy Ions
• Neutrinos
• QCD

 

This conference is also hosting a special DOE  component featuring plenary presentations on funding opportunities and the longer term physics direction. Afternoon sessions dedicated to specific  "Frontier" programs are scheduled and opportunties for PIs to meet with their program managers are anticipated. 

All of the plenary and parallel sessions will be convened in the Michigan League, in the heart of the University of Michigan Central Campus. Welcome reception, breakfasts and coffee breaks are provided in the Michigan League Ballroom in order to foster extended discussions during the week.

Accommodations are provided in either university dormitory and hotels right on campus, or in off-campus hotels connected by shuttles or public transportation. Limited financial aid covering the cost of accommodations for students and post-doc is available on a first-come first-serve basis.

Note: To submit/view an abstract you will need to logon to the CERN Indico server. This may be done through:
1) A CERN user account
2) A public service account such as Gmail, Facebook, Live, etc.
3) A CERN Lightweight account. This mayeasily be obtained via the instructions in the link.

This service allows external users who do not have a regular CERN account to get access to certain CERN applications that are open to external users. The CERN Lightweight Account consists in your existing email address and a password.

DPF-Template.doc

DPF-Template.pdf

Tuesday 4 August

07:30 Breakfast

Session I-A

Convener: Gordon Kane (University of Michigan)

1 Welcome from University of Michigan President Mark Schlissel

Speaker: Mark Schlissel (University of Michigan)

2 Welcome and Opening

Speaker: Homer Neal (University of Michigan (US))

3 Welcome from the DPF

This will be a welcome talk from the DPF

Speaker: nicholas hadley

Ann_Arbor_DPF_Chair_Intro.pdf

Ann_Arbor_DPF_Chair_Intro.pptx

4 LHC Run 2 Startup

After the very successful Run 1, the LHC accelerator and experiments had undergone intensive consolidation, maintenance and upgrade activities during the first long shutdown (LS1). This presentation will briefly report the major LS1 experiment activities and review the readiness for Run 2 data taking.

Speaker: Jinlong Zhang (Argonne National Laboratory (US))

Zhang_20150804.pdf

5 Pentaquarks and Tetraquarks at LHCb

Observations of exotic structures in the j\psi p channel, that we refer to as pentaquark-charmonium states, in Lamda_b to j\psi p K^- decays are presented. The data sample corresponds to an integrated luminosity of 3 inverse femtobarns acquired with the LHCb detector from 7 and 8 TeV pp collisions. An amplitude analysis is performed on the three-body final state that reproduces all the angular and two-body mass distributions in the decay chain. To obtain a satisfactory fit of the structures seen in the j\psi p mass spectrum, it is necessary to include two Breit-Wigner amplitudes that each describe a resonant state. We also discuss the related amplitude analysis that measured unambiguously the spin-parity of the Z_c(4430)^+ state that decays into psi' pi^+

Speaker: Sheldon Stone (Syracuse University (US))

Pentaquark-DPF.pdf

Pentaquark-DPF.pdf

10:15 Cafe Break

Session II-A

Convener: Raymond Brock (Michigan State University)

6 BSM: Theory

Speaker: Prof. Josh Ruderman (NYU)

JoshDPF.pdf

7 Searches for New Physics at the Energy Frontier

I will give an overview of searches for new physics at the Large Hadron Collider. I will discuss lessons learned from Run-1, outline the anomalies in the current data-set, and plan to present the first Run-2 results at 13 TeV.

Speaker: John Alison (University of Chicago (US))

BSMReview.pdf

8 DOE-HEP Program and FOAs

Speaker: Glen Crawford (DOE)

2015-08-04 DOE HEP Program Status and Funding Opportunities v5c.pdf

12:30 Lunch

AstroParticle, Cosmology, Dark Matter Searches, and CMB

Convener: Rachel Mandelbaum (Carnegie Mellon University)

9 New Science with the Dark Energy Survey

The Dark Energy Survey (DES) is a large imaging survey of the southern sky designed to shed new light on the nature of the dark physics behind the accelerated expansion of the Universe. The DES collaboration built and participated in the installation and commissioning of DECam, a 570 mega-pixel optical and near-infrared camera with a large 3 deg$^2$ field of view, set at the prime focus of the Víctor M. Blanco 4-meter telescope in at the Cerro Tololo Inter-American Observatory in Chile. Using DECam, DES will map 5000 deg$^2$ to a typical depth $I_{AB}\sim24$. These data will allow DES to make precision measurements for 300 million galaxies, the light-curves of several thousand supernovae, and the masses of tens of thousands of galaxy clusters. With these data, DES will use four main probes to study the properties of dark energy: galaxy clustering on large scales, weak gravitational lensing, galaxy-cluster abundance, and supernova distances. I describe the early progress of the survey and provide highlights of the science analyses that have been completed so far. These include large-scale galaxy clustering measurements; significant detection of a cross-correlation with South Pole Telescope CMB lensing maps; galaxy-shear and shear-shear correlation function measurements; discoveries of super-luminous supernovae, dozens of strong lenses, and redshift $> 6$ quasars; and characterization of DES galaxy clusters and SNe1a light-curves.

Speaker: Eric Huff (Ohio State University)

10 Supernovae & The Dark Energy Survey

Type Ia supernovae (SNe Ia) are crucial observational tools for exploring the accelerated expansion of the universe. These brilliant explosions are one of the fundamental probes of the Dark Energy Survey (DES) - an international collaboration aiming to understand the mysterious Dark Energy. In the first few years of the survey, the SN Ia group has made exciting progress in SN Ia discovery and pipeline development. This talk will highlight some of the efforts of the DES SN Ia group and describe plans for the future.

Speaker: Ms Rachel Wolf (University of Pennsylvania)

WOLFDPF2015.pdf

11 The Dark Energy Survey - First Results in Galaxy Cluster Weak Lensing

We present the first set of galaxy cluster weak lensing results from the Dark Energy Survey (DES) Science Verification data. The Science Verification (SV) run, approximately 160 square degrees of multi-epoch imaging in four frequency bands, contains data for thousands of clusters, many of which have been newly discovered by DES. The DES-SV area also contains regions that overlap with footprints of other cluster-finding surveys, such as the South Pole Telescope (SPT) Cluster Survey and the X-ray Multi-Mirror Mission (XMM) Cluster Survey (XCS). We use DES optical data to perform weak lensing analysis on several sets of clusters, some found entirely by DES, and others found by the overlapping cluster surveys. Some of these samples allow us to measure the relationships between weak lensing mass and other cluster observables, such as X-ray temperature. By also performing mass calibration measurements on previously-known clusters, we examine systematic effects in the DES-SV data and verify that the survey data quality is adequate for expected science analysis in future years.

Speaker: Rutuparna Das (University of Michigan)

DPF2015 presentation4.pdf

DPF2015 presentation5.pdf

12 Discovery of Milky Way dwarf galaxies in the Dark Energy Survey and implications for cosmological models

The census of Milky Way satellite galaxies provides crucial tests of both galaxy formation models and the broader Cold Dark Matter paradigm. The discoveries of many dwarf galaxies from the Sloan Digital Sky Survey have also provided insight on the nature of dark matter and the reionization of the universe. It is estimated that many hundreds of ultra-faint Milky Way companions will be discovered with on-going and near-future wide-field optical imaging surveys at fainter luminosities, greater distances, and in less explored regions of the sky. The Dark Energy Survey (DES) is one such survey now in the process of imaging 5000 square degrees of the southern sky in the grizY bands down to r~24 mag. We present here the results of a recent search for new satellite galaxies in the Dark Energy Survey data. So far, a dozen new stellar systems have already been reported in 2015, one of which, Reticulum II, has now been dynamically and chemically confirmed as a dwarf galaxy. We place these recent results in context and briefly discuss some of the implications for tests of fundamental physics.

Speaker: Ting Li

TingLiAPSDPF2015.pdf

Neutrino Physics

Conveners: Daniel Hernandez, Irina Mocioiu (Pennsylvania State University), Lindley Winslow (Massachusetts Institute of Technology), Lisa Kaufman (I)

13 Latest results/analysis in Double Chooz

Precise measurement of the neutrino mixing angle theta13 is the primary goal of the Double Chooz Experiment. Inverse beta decay process provides a unique signature of anti-neutrino interaction from the reactors, giving prompt signals from positron annihilation and delayed signals from neutron capture by either Gadolinium (Gd) or Hydrogen (H). In this talk, the latest Gd- and H-based analysis results from Double Chooz will be presented, including the detection efficiency evaluation, background estimates, energy calibration and oscillation results.

Speaker: Mr Guang Yang (Argonne National Lab/Illinois Institute of Technology)

DPF2015.pdf

14 Super Kamiokande Atmospheric Neutrino Analysis

Super Kamiokande atmospheric neutrino data is sensitive to multiple oscillation parameters. Of particular current interest are the neutrino mass hierarchy, $\theta_{23}$ octant, and leptonic cp violating phase. I will discuss newly updated SK atmospheric neutrino oscillation results spanning SK I-IV, which corresponds to 306 kT-years of data. I will additionally discuss results of a combined fit to SK atmospheric and publicly available T2K data, which tightens the constraints on these parameters.

Speaker: Chris Kachulis

SK_atmospheric_kachulis_dpf2015.pdf

15 Search for exotic transitions of muon neutrinos to electron neutrinos with MINOS

The observed neutrino flavor transitions are currently explained by the three flavor neutrino oscillation phenomenon, considered to be the leading order mechanism behind the flavor transitions. Currently existing data from LSND, miniBooNE and reactor experiments demonstrate anomalies that could potentially be indications of non-standard neutrino phenomena. MINOS can probe transitions from muon neutrinos to electron neutrinos and search for anomalous behavior that cannot be explained by standard model neutrino oscillations. Here we present the search for second order effects in the flavor transitions by analyzing the MINOS $\nu_\mu \to \nu_e$ channel.

Speaker: Dr Marianna Gabrielyan (University of Minnesota)

DPF2015_MGabrielyan.pdf

DPF2015_MGabrielyan.pdf

16 Search for flavor changing non-standard interactions with the MINOS+ experiment

MINOS+ began operation in September 2013 as an extension of the MINOS experiment, and extends the study of neutrino oscillations as well as the search for exotic physics such as flavor changing non-standard interactions (NSI) over a baseline of 735 km. To date MINOS+ has reported the most precise measurement of neutrino oscillations in the atmospheric sector from a three-neutrino flavor analysis of the full $14.3 \times 10^{20}$ PoT MINOS era beam sample combined with the full MINOS and MINOS+ atmospheric neutrino samples. MINOS/MINOS+ is able to separately produce well understood beams enriched in neutrinos and antineutrinos and to identify neutrinos and antineutrinos on an event-by-event basis in its magnetized detectors. This allows sensitive searches for NSI in the mu-tau and e-tau sectors. We present preliminary results using the full MINOS beam data set.

Speaker: Nicholas Joseph Graf (University of Pittsburgh (US))

Graf_MinosNSI_DPF2015.pdf

17 An Experimental Program in Neutrinos, Nucleon Decay and Astroparticle Physics Enabled by the Fermilab Long-Baseline Neutrino Facility

A new International Team (DUNE - Deep Underground Neutrino Experiment) has been formed to pursue an accelerator-based long-baseline neutrino experiment, as well as neutrino astrophysics and nucleon decay, with an approximately 40-kt (fiducial) modular liquid argon TPC (LAr-TPC) detector located deep underground and a high-resolution near detector. Several independent worldwide efforts, developed through years of detailed studies, are converging around the opportunity provided by the megawatt neutrino beam facility planned at Fermilab and by the new significant expansion with improved access at the Sanford Underground Research Facility in South Dakota, 1,300 km from Fermilab. The principle goals of this experiment are: a comprehensive investigation of neutrino oscillations to test CP violation in the lepton sector, determine the ordering of the neutrino masses, and test the three-neutrino paradigm; to perform a broad set of neutrino scattering measurements with the near detector; and to exploit the large, high-resolution, underground far detector for non-accelerator physics topics including atmospheric neutrino measurements, searches for nucleon decay, and measurement of astrophysical neutrinos especially those from a core-collapse supernova.

Speaker: James Allen Stewart (Brookhaven National Laboratory (US))

DUNE-Stewart-v3.pdf

DUNE-Stewart-v3.pptx

EWK and Higgs Sector: Higgs coupling

Convener: Sally Dawson (BNL)

18 Effective Lagrangians for Higgs Physics

After the discovery of the Higgs at the LHC, and as the data continues to converge to the Standard Model predictions, it becomes important to try and classify possible small deviations from the expected behavior. A manner of doing so, consistent with the symmetries of the Standard Model, is the use of effective field theories. They are valid both for scenarios with new ultraviolet decoupling physics, with an elementary Higgs-like particle in the spectrum, as well as new strongly interacting scenarios where the degrees of freedom may present as pseudo Goldstone bosons of some new global symmetry such as composite Higgs models. In this talk we will work in the effective field theory framework and using the available experimental data as well as unitarity considerations we show the present status on the determination of the coefficients of the relevant effective operators for Higgs physics. The talk will follow the publications: arXiv:1411.5026, 1311.1823, 1304.1151, 1211.4580, and 1207.1344

Speaker: Tyler Corbett (Stony Brook)

Corbett_Tyler_DPF15.pdf

19 Measurement of the Higgs boson coupling strengths in the ATLAS experiment

This talk presents the combined measurement of the Higgs boson coupling strengths using the full Run I data sample recorded by the ATLAS detector. Results from the H->γγ, ZZ*, WW*, Zγ, ττ, bb and μμ decay modes are presented, as well as constraints on associated Higgs production with a top quark pair and on the off-shell coupling strengths of the Higgs boson. For all benchmark models considered, the data are found to be compatible with the expectations for a Standard Model Higgs boson.

Speaker: Fangzhou Zhang (University of Wisconsin (US))

slides.pdf

Quark and Lepton Flavor Physics

Conveners: J Michael Williams (Massachusetts Inst. of Technology (US)), Jure Zupan (University of Cincinnati)

20 BSM and Flavor

Speaker: Wolfgang Altmannshofer (Perimeter Institute)

altmannshofer_DPF.pdf

21 Rare electroweak B decays at LHCb

Speaker: Espen Eie Bowen (Universitaet Zuerich (CH))

DPF-2015-EWP-Bowen.pdf

22 Bs0 → φμ+μ− at LHCb

Speaker: Michael Kolpin (Ruprecht-Karls-Universitaet Heidelberg (DE))

Bs2PhiMuMu.pdf

BSM Physics

Conveners: Kevin Black (Boston University), Nathaniel Craig (UC Santa Barbara), Rouven Essig

23 ATLAS results in the search for a charged Higgs boson

While the Standard Model has proven very successful in describing particle interactions, several unanswered questions still remain. Alternative models, such as those with an extended Higgs sector, can be consistent with current observations and answer some of these questions. In the class of models with extended Higgs sectors known as Two-Higgs-doublet models, five physical Higgs bosons are predicted, two of which are charged. The latest ATLAS search for a Charged Higgs boson is based on 19.5 fb−1 of proton-proton collision data at centre-of-mass energy of 8 TeV collected by the ATLAS experiment at the Large Hadron Collider. Charged Higgs bosons are searched for in the decay of top-quark pairs or in direct production in association with a top quark, depending on the considered charged Higgs boson mass. The final state is characterized by the presence of a hadronic tau decay, missing transverse momentum, b-tagged jets, a hadronically-decaying W boson, and the absence of any isolated electrons or muons with high transverse momenta. The analysis strategy and results of this search will be presented.

Speaker: Allison Renae Mc Carn (University of Michigan (US))

DPF_ChargedHiggs.pdf

24 Search for non Standard Model Higgs boson decays in events with displaced muon-jets

New light bosons that couple weakly to the standard model (SM) are predicted in various extensions of the standard model (BSM). Examples include supersymmetric (SUSY) theories with extended Higgs sectors (NMSSM) or with a hidden valleys (dark SUSY). In these models the light bosons can be produced directly in the decay of a Higgs boson, or as part of the decay chain of SUSY particles. Depending on the branching ratio, the exotic decays of the SM-Higgs can either hide the Higgs boson in standard analyses, slightly change the SM Higgs boson production cross section at the LHC. Therefore, direct searches for non-SM decays of the Higgs boson are the fastest way to understand the nature of the Higgs. Either it will confirm its SM character, or it will rule out a whole array of BSM scenarios. We present status of the search at CMS for non-SM Higgs boson decays in events with displaced muon-jets.

Speaker: Sven Dildick (Texas A & M University (US))

DPF2015_SvenDildick.pdf

25 Search for a heavy Higgs boson decaying to ZZ diboson with the ATLAS Detector

This talk presents searches in ATLAS for a heavy Higgs boson decays to ZZ diboson with four different experimental final states: four charged leptons, two charged leptons and missing transverse energy, two charged leptons and two jets, and two jets and missing transverse energy. The analyses use 20.3 fb^-1 of proton-proton collision data at sqrt(s) = 8 TeV. Results are interpreted in a model-agnostic approach, as well as in Type-I and Type-II two-Higgs-doublet models.

Speaker: Laser Seymour Kaplan (University of Wisconsin (US))

dpf2015_laser_highmasshzz.pdf

26 Search for Higgs bosons decaying to aa in the μμττ final state in pp collisions at √s = 8 TeV with the ATLAS experiment

We present a search for the exotic decay of the SM-like Higgs boson (h), or the production of a second CP-even Higgs boson (H) decaying to a pair of neutral pseudoscalar Higgs bosons (a), in the next-to-minimal supersymmetric standard model (NMSSM), in events with two muons from the decay of one a boson, with the ATLAS detector in 20.3 /fb of √s = 8 TeV pp collisions. Events are further required to have an additional muon or an electron, with nearby tracks, consistent with decay of the second a boson to two taus. An upper limit on the production rate of h→aa, relative to the SM production, is set as a function of m_a in the range from 3.7 to 50 GeV. An upper limit is also placed on the production rate of H→aa for m_a = 5 GeV and m_H ranging from 100 to 500 GeV.

Speaker: Benjamin Eric Kaplan (New York University (US))

Kaplan_APS_DPFAugust2015_h2aa.pdf

27 ATLAS results in the search for a CP-odd Higgs boson decaying to Zh, in final states with 2 taus and 2 electrons or muons

While the Standard Model has proven very successful in describing particle interactions, several unanswered questions still remain. Alternative models, such as those with an extended Higgs sector, can be consistent with current observations and answer some of these questions. This talk presents a search for a heavy, CP-odd Higgs boson, A, decaying into a Z boson and a 125 GeV Higgs boson, h, with the ATLAS detector at the LHC. The search uses proton–proton collision data at a centre-of-mass energy of 8 TeV corresponding to an integrated luminosity of 20.3 fb−1. Decays of CP-even h bosons to ττ pairs with the Z boson decaying to electron or muon pairs are considered. The analysis strategies and final results of the search will be presented, as well as a combined result with several other A->Zh decay modes.

Speaker: Allison Renae Mc Carn (University of Michigan (US))

DPF_AZh.pdf

28 Type-III seesaw fermionic triplets at the International Linear Collider

We investigated the signature of heavy fermionic triplets belonging to Type III seesaw model through their direct production at the International Linear Collider (ILC). In particular we looked into the decay distributions of charged ($\Sigma^{\pm}$) and neutral ($\Sigma^{0}$) triplets in the processes $e^{+} e^{-} \rightarrow \Sigma^{+}\Sigma^{-}, \Sigma^{0} \Sigma^{0}, \Sigma^{0}\nu, \Sigma^{\pm}\ell$ and studied how they can be used to reduce the SM background. These heavy triplets mix with SM leptons and thus opens up the possibility of studying various interesting channels. The triplet state($\Sigma$) having mass around 250 GeV, will be produced in large numbers at the ILC with CM energy of 1000 GeV and a moderate integrated luminosity of 300 $fb^{-1}$. Further we have found that it is possible to distinguish scenarios involving different mixings.

Speaker: Ms Deepanjali Goswami (Indian Institute of Technology Guwahati, INDIA)

LHC Run-2 Detector Performance

Conveners: Anyes Taffard (University of California Irvine (US)), Petra Merkel (Fermi National Accelerator Lab. (US))

29 The CMS Silicon Tracker Performance during early LHC Run II

The CMS silicon tracker went through a series of improvements during the first LHC long shutdown to prepare for the LHC Run II challenge. The startup conditions at 13 TeV for both subdetectors will be summarised, including specifics for 50ns and 25ns operations and improvements in calibrations which were developed during 2013 and 2014. Early LHC Run II performance of the CMS Pixel and Strip Silicon Tracker will be presented together with the expected performance at high pile-up.

Speaker: Petra Merkel (Fermi National Accelerator Lab. (US))

DPF15_CMSTracker_080415.pdf

30 Commissioning and Performance of the upgraded ATLAS Pixel Detector for Run2

The Pixel Detector of the ATLAS experiment has shown excellent performance during the whole Run-1 of the Large Hadron Collider. Taking advantage of the long shutdown, the detector was extracted from the experiment and brought to surface, to repair modules and to ease installation of the Insertable B-Layer (IBL). The IBL is a fourth innermost layer of the pixel detector, and was installed in May 2014 between the existing Pixel Detector and the new smaller radius beam-pipe at a radius of 3.3 cm. To cope with the high radiation and pixel occupancy anticipated due to the proximity to the interaction point, a new read-out chip, two different silicon sensor technologies (planar and 3D) and off-detector electronics have been developed. A new mechanical support using lightweight staves and a CO2 based cooling system have been adopted to reduce the material budget. An overview of the refurbishing of the Pixel Detector and of the Insertable B-Layer (IBL) project as well as commissioning and performance tests using cosmic and beam data will be presented.

Speaker: Shih-Chieh Hsu (University of Washington, Seattle)

schsu_DPFPixel.pdf

31 CMS Silicon Tracker Alignment: First Run2 Results

The all-silicon design of the tracking system of the CMS experiment provided excellent resolution for charged tracks and an efficient tagging of jets during Run1 of the LHC. As the CMS tracker, and in particular its pixel detector, underwent repairs and experienced changed conditions with the start of Run2 this year, the position and orientation of each of the 15148 silicon strip and 1440 silicon pixel modules needed to be determined with a precision of several micrometers. The local hit reconstruction required new calibration. We present the first Run2 results of the CMS tracker alignment, calibration, and resolution performance using several million reconstructed tracks from the cosmic data and the first collision data. The achieved resolution in all five track parameters is controlled with data-driven validation of the track parameter measurements near the interaction region, and tested against prediction with detailed detector simulation. Implications for CMS physics performance are discussed.

Speaker: Heshy Roskes (Johns Hopkins University (US))

CMSTrackerAlignmentResults_DPF.pdf

CMSTrackerAlignmentResults_DPF.pptx

Accelerators, Detectors, Computing

Conveners: Daniel Winklehner (Massachusetts Institute of Technology), Joel England (Stanford)

32 IsoDAR and DAEdALUS: The next generation of cyclotrons for neutrino physics

The DAEdALUS program seeks to construct a number of high power cyclotrons for neutrino physics. The first step in the phased program, IsoDAR, will combine a high power, low energy cyclotron with a liquid scintillator based detector in order to, among other measurements, directly probe the experimental anomalies often attributed to neutrino oscillations involving one or more light sterile neutrinos. I will provide an update on the overall DAEdALUS effort with a focus on the progress towards constructing the 60 MeV/nucleon IsoDAR accelerator.

Speaker: Joshua Spitz (MIT)

spitz_dpf_isodar_daedalus_2015.pdf

33 Early Beam Injection Scheme for the Fermilab Booster: A Path for Intensity Upgrade

After the shutdown of the Tevatron, Fermilab has shifted focus to the intensity frontier and is committed to increase the average beam power to the neutrino and muon programs. Many upgrades to the existing injector accelerators are in progress under the Proton Improvement Plan (PIP). Proton Improvement Plan –II proposes to build an 800 MeV LINAC (that adopts super conducting RF technology) adding to the existing facility in the complex. In any case, the Fermilab Booster, an 8 GeV injector to 120 GeV Main Injector, is going to play very significant role for nearly next two decades. In this context, very recently we have proposed a new beam injection scheme called "early injection scheme" for the Fermilab Booster that has a high potential to increase the beam intensity output from the Booster, resulting in increased beam power to the HEP experiments. The scheme, if implemented, could also help improve the slip-stacking efficiency in the MI/RR with further gains in beam power. Here we present results from recent beam studies, current status of operational implementation and future plans for the early beam injection scheme.

Speaker: Dr Chandra Bhat (Fermilab)

DPF2015-cbhat-Fermilab.pdf

DPF2015-cbhat-Fermilab.pptx

34 500 GeV ILC Operating Scenarios

The ILC Technical Design Report documents the design of a 500 GeV linear collider, but does not specify the centre-of-mass energy steps of operation for the collider. The ILC Parameters Joint Working Group has studied possible running scenarios, including a realistic estimate of the real time accumulation of integrated luminosity based on ramp-up and upgrade processes, considering the evolution of the physics outcomes. These physics goals include Higgs precision measurements, top quark measurements and searches for new physics. We present this "optimized" operating scenario and the anticipated evolution of the precision of the ILC measurements.

Speaker: James Brau (University of Oregon (US))

Parameters_DPF.pdf

35 HEPAP Accelerator R&D Subpanel

A summary of results of the HEPAP Accelerator R&D Subpanel will be presented along with the implications for future accelerator R&D in the United States. The final report of the Subpanel will be available on the HEPAP website in early June.

Speaker: Prof. Don Hartill (Cornell University)

DPF2015-Don Hartill.pdf

DPF2015-Don Hartill.pptx

36 Crystal Ball : On the Future High Energy Colliders

Particle colliders for high-energy physics have been in the forefront of scientific discoveries for more than half a century. The accelerator technology of the colliders has progressed immensely, while the beam energy, luminosity, facility size, and cost have grown by several orders of magnitude. The method of colliding beams has not fully exhausted its potential but has slowed down considerably in its progress. I will briefly review known costs for 17 large accelerators based on traditional technologies (RF, magnets, etc),and examine feasibility of near- or medium-term collider projects that are currently subjects of design work or under active discussions. I will conclude with an attempt to look beyond the current horizon and to find what paradigm changes are necessary for breakthroughs in the field, and describe some R&D programs at FNAL which prepare for the long-term future, e.g. studies with crystals and the IOTA ring research.

Speaker: Dr Vladimir Shiltsev (Fermilab)

DPF2015_Shiltsev_v3.pdf

DPF2015_Shiltsev_v3.pptx

QCD and Heavy Ions

Convener: Radja Boughezal (Argonne National Laboratory)

QCDTevDPF2015.pdf

37 QCD results from ATLAS and CMS

Speaker: Emanuela Barberis (Northeastern University (US))

QCD-DPF-Barberis.pdf

QCD-DPF-Barberis.pptx

38 Overview of Precision QCD

This is an overview of recent developments in precision QCD.

Speaker: Dr Xiaohui Liu (University of Maryland)

dpftalk-xhliu-1.pdf

39 Precision QCD for LHC New Physics Searches: Working with heavy quarks at High Scales & High Orders

Searches for new physics at the LHC will increasingly depend on identifying deviations from precision Standard Model predictions. At the higher energy scales involved for the LHC Run 2, the heavy quarks play a more prominent role than at the Tevatron. Recent theoretical developments improve our ability to address multi-scale problems and properly incorporate heavy quark masses across the full kinematic range. This includes a Hybrid Variable Flavor Number Scheme (H-VFNS) for heavy flavors, and the extension of the ACOT scheme for heavy quark production to N2LO and N3LO. We review these developments with respect to upcoming Run 2 measurements, and identify areas where additional effort is required.

Speaker: Fred Olness (Southern Methodist University)

olness_dpf2.pdf

Top Physics

40 N^3LO threshold corrections for top-pair and single-top production

I present a calculation of higher-order corrections from NNLL threshold resummation for cross sections and differential distributions in top-antitop pair production and in single-top production. I show that soft-gluon threshold corrections are the dominant contribution to top-quark production and closely approximate exact results through NNLO. I show aN$^3$LO results for the total $t{\bar t}$ cross section, the top-quark $p_T$ and rapidity distributions, and the top-quark forward-backward asymmetry. I also present aNNLO results for total cross sections and $p_T$ distributions in $t$-channel, $s$-channel, and $tW$-channel single-top production.

Speaker: Nikolaos Kidonakis (Kennesaw State University)

Kidonakis.pdf

41 Measurements of the Top Quark Cross Section with the ATLAS Experiment

The most up-to-date top quark pair production cross section measurements will be presented for p-p collisions with the ATLAS detector at the LHC. Both differential and inclusive measurements will be discussed, as well as analyses focusing on rare decays such as top quark pairs associated with an additional boson or jets. The results will be discussed in the context of new physics, Monte Carlo modeling, and PDF's.

Speaker: Thomas Andrew Schwarz (University of Michigan (US))

DPF2015-ttXsection.pdf

42 Top pair production inclusive and differential production cross section measurements in pp collisions

Top pair production cross-section measurements and theoretical predictions have achieved unprecedented precision. A review is presented of recent top-quark pair inclusive and differential production cross sections in proton-proton collisions at the LHC at centre-of-mass energies of 7 and 8 TeV, using data collected by the CMS experiment in the years 2011 and 2012. The differential cross-sections are measured as functions of various kinematic observables. All results are compared with theoretical predictions.

Speaker: Dr Gabriele Benelli (University of Kansas and Fermilab LPC Distinguished Researcher)

15:30 Cafe Break

AstroParticle, Cosmology, Dark Matter Searches, and CMB

Convener: Hugh Lippincott (FNAL)

43 A search for dark matter annihilation in the newly discovered dwarf galaxy Reticulum 2

I will present results from a search for gamma-ray emission in nine Milky Way satellites recently discovered in the Dark Energy Survey. The nearest of these, Reticulum 2, shows evidence for a signal in public Fermi data. The detected emission is consistent with annihilating dark matter with a particle mass less than a few hundred GeV. Different ways of treating the background yield different significances -- ranging from 2.3 sigma to greater than 3.7 sigma (after trials) -- and I will discuss the caveats involved. I will discuss tests that any dark matter interpretation must pass.

Speaker: Alex Geringer-Sameth (Carnegie Mellon University)

Alex_Geringer-Sameth_Ret2.pdf

44 Dark matter inferred from stellar kinematics in the smallest galaxies

Images from the Dark Energy Survey have recently revealed a new population of dwarf-galactic satellites of the Milky Way. Based on their proximity, sizes and low luminosities, several of the new objects are attractive targets in searches for products of dark matter annihilation. I will summarize current astrophysical results for the nearest of the new dwarf galaxies, Reticulum II, and will discuss prospects for estimating the dark matter content of the new objects based on stellar spectroscopy.

Speaker: Matthew Walker (Carnegie Mellon University)

m_walker.pdf

45 Fermi/LAT observations of Dwarf Galaxies highly constrain a Dark Matter Interpretation of Excess Positrons seen in AMS-02, HEAT, and PAMELA

It is shown that a Weakly Interacting Massive dark matter Particle (WIMP) interpretation for the positron excess observed in a variety of experiments, HEAT, PAMELA, and AMS-02, is highly constrained by the Fermi/LAT observations of dwarf galaxies. In particular, this paper has focused on the annihilation channels that best fit the current AMS-02 data (Boudaud et al., 2014). The Fermi satellite has surveyed the $\gamma$-ray sky, and its observations of dwarf satellites are used to place strong bounds on the annihilation of WIMPs into a variety of channels. For the single channel case, we find that dark matter annihilation into {$b\bar{b}$, $e^+e^-$, $\mu^+\mu^-$, $\tau^+\tau^-$, 4-$e$, or 4-$\tau$} is ruled out as an explanation of the AMS positron excess (here $b$ quarks are a proxy for all quarks, gauge and Higgs bosons). In addition, we find that the Fermi/LAT 2$\sigma$ upper limits, assuming the best-fit AMS-02 branching ratios, exclude multichannel combinations into $b\bar{b}$ and leptons. The tension between the results might relax if the branching ratios are allowed to deviate from their best-fit values, though a substantial change would be required. Of all the channels we considered, the only viable channel that survives the Fermi/LAT constraint and produces a good fit to the AMS-02 data is annihilation (via a mediator) to 4-$\mu$, or mainly to 4-$\mu$ in the case of multichannel combinations.

Speaker: Alejandro Lopez

Fermi-AMS-02.pptx

46 Constraining Unresolved Point Source Contributions to the GeV Excess with Probabilistic Catalogues

Several groups have identified a highly significant and spatially extended excess of GeV gamma-rays in the Inner Galaxy using data from the Fermi LAT. While this signal’s properties are consistent with those expected from dark matter annihilation, another interpretation is that it is the emission from a population of unresolved millisecond pulsars. We implement a Bayesian method for producing probabilistic point source catalogues from the Fermi LAT data to test this interpretation. By using a distribution of catalogues that is consistent with the data, we constrain the luminosity function of any unresolved point sources contributing to the GeV excess.

Speaker: Stephen Portillo (Harvard University)

DPF-Talk.pdf

DPF-Talk.pptx

47 Antideuteron Signatures of Dark Matter with the GAPS Experiment

Recent years have seen increased theoretical and experimental effort towards the first-ever detection of cosmic-ray antideuterons, in particular as an indirect signature of dark matter annihilation or decay in the Galactic halo. In contrast to other indirect detection signatures, which have been hampered by the large and uncertain background rates from conventional astrophysical processes, low-energy antideuterons provide an essentially background-free signature of dark matter. This signal probes a broad class of dark matter candidates and is particularly sensitive to low-mass WIMP dark matter, both complementing current experiments and offereing a potential breakthrough in unexplored dark matter phase space. In this contributuion, I will present the theoretical motivation for dark matter searches with antideuterons and the dominant theoretical uncertainties associated with antideuteron flux predictions, specifically nuclear formation and cosmic-ray propagation in the Galactic and Solar environments. I will then introduce the currently planned or ongoing experiments that will be sensitive to the flux levels predicted for dark matter, focusing on the baloon-borne GAPS experiment, which exploits a novel detection technique utilizing exotic atom capture and decay to provide both a sensitive antideuteron search and a precision antiproton measurement in an unprecedented low-energy range.

Speaker: Kerstin Perez

KPerez_DPF2015_20150804.pdf

48 Prospects for Measuring the Positron Excess with the Cherenkov Telescope Array

The excess of positrons in cosmic rays above ∼10 GeV has been a puzzle since it was discovered. Possible interpretations of the excess include acceleration in local supernova remnants or pulsars, or the annihilation or decay of dark matter particles. To tell the difference, the positron fraction must be measured at higher energies. One technique to perform this measurement is using the Earth-Moon spectrometer: observing the deflection of positron and electron moon shadows by the Earth’s magnetic field. The measurement has been attempted by previous imaging atmospheric Cherenkov telescopes without success. The Cherenkov Telescope Array (CTA) will have unprecedented sensitivity and background rejection that could make this measurement successful for the first time. In addition, the possibility of using silicon photomultipliers in some of the CTA telescopes could greatly increase the feasibility of making observations near the moon. Estimates of the capabilities of CTA to measure the positron fraction using simulated observations of the moon shadow will be presented.

Speaker: Peter Karn (University of Wisconsin - Madison)

Neutrino Physics

Conveners: Daniel Hernandez, Irina Mocioiu (Pennsylvania State University), Lindley Winslow (Massachusetts Institute of Technology), Lisa Kaufman (Indiana University)

49 DUNE: the Physics Potential of a Large, Underground, Liquid Argon Neutrino Detector

The Deep Underground Neutrino Experiment (DUNE) proposes to build four 10-kt liquid argon time projection chambers (LArTPCs) which will constitute what is known as the Far Detector in the Long-Baseline Neutrino Facility. These LArTPCs will be placed 4850 feet underground at the Sanford Underground Research Facility (SURF) in Lead, SD. The overburden provided by SURF will allow DUNE the opportunity to study a variety of phenomena such as supernova neutrinos, nucleon decay, and oscillation effects from atmospheric neutrinos. A brief overview of the underground physics potential of DUNE will be given, and the challenges involved in supernova neutrino triggering and detection in liquid argon will be presented in detail.

Speaker: Chris Grant (UC Davis)

DUNE_UndergroundPhysics_Grant_2015.pdf

50 The LBNF Beamline

The LBNF beamline complex is designed to provide a neutrino beam of sufficient intensity and energy to meet the goals of the DUNE experiment with respect to long-baseline neutrino oscillation physics. Presented in this talk will be the issues related to the baseline design from the physics, beam power (>1 MW), lifetime, and radiological requirements. Potential future upgrades to the beamline to improve the neutrino flux spectrum and for higher beam power (>2 MW) will also be presented.

Speaker: Maury Goodman (Argonne)

51 LBNO-DEMO (WA105): a large demonstrator of the Liquid Argon double phase TPC

A giant (10-50 kt) Liquid Argon Time Projection Chamber (LAr-TPC) has been proposed as the detector for an underground observatory for the study of neutrino oscillations, neutrino astrophysics and proton decay. This detector has excellent tracking and calorimetric capabilities, much superior to currently operating neutrino detectors. LBNO-DEMO (WA105) is a large demonstrator of the double phase LAr-TPC based on the GLACIER design, with a 6$\times$6$\times$6~m$^3$ (appr. 300t) active volume. Its construction and operation test scalable solutions for the crucial aspects of this detector: ultra-high argon purity in non-evacuable tanks, long drifts, very high drift voltages, large area Micro Pattern Gas Detectors (MPGD), and cold preamplifiers. The TPC will be built inside a tank based on industrial technology developed for liquefied natural gas transportation. Electrons produced in the liquid argon are extracted in the gas phase. Here, a readout plane based on Large Electron Multiplier (LEM) detectors provides amplification before the charge collection onto an anode plane with strip readout. Photomultiplier tubes located on the bottom of the tank containing the liquid argon provide the readout of the scintillation light. This demonstrator is an industrial prototype of the design proposed for a large underground detector. WA105 is under construction at CERN and will be exposed to a charged particle beam (0.5-20 GeV/c), consisting of $p, e^{\pm}, \pi^{\pm}$ and $K^{\pm}$, in the North Area in 2018. The data will provide necessary means for analysing and developing shower reconstruction, energy response and calibration, MC event generator tuning, particle identification, and tracking, as well as related efficiencies, and for development of analysis tools. This project is a crucial milestone providing feedback for future long baseline experiments considering LAr-TPCs.

Speaker: Sebastien Murphy (Eidgenoessische Tech. Hochschule Zuerich (CH))

DPF_WA105_smurphy.pdf

52 Characterization of New Meter Scale Light Guides for Liquid Argon TPC Light Collection

The ability to detect 128 nm scintillation light from liquid argon (LAr) is of critical importance in current and future liquid argon time-projection chamber (LarTPC) experiments. To this end, tetraphenyl butadiene (TPB) has been employed in light collection systems to shift 128 nm light to visible wavelengths. Work has been done recently using TPB in conjunction with light guides to improve light collection. We have developed improved techniques for producing TPB coated acrylic light guides with attenuation lengths exceeding 1 m when measured in air. These improvements have come from a new acrylic based coating as well as a new technique for applying the coating. Measurements taken in both air and LAr have allowed us to create a model connecting the behavior in LAr with that in air which is in good agreement with data. This model can be used in simulations for future lightguide based experiments, such as SBND and DUNE. It also allows quality control of new light guides without requiring costly measurements in LAr.

Speaker: Jarrett Moon (MIT)

Jarrett Moon DPF Talk August 4.pdf

53 First Run of the LArIAT Testbeam Experiment

The liquid argon time projection chamber (LArTPC) is a relatively new and powerful technology favored by several current and future neutrino experiments. Its ability to resolve particle interactions as detailed three-dimensional images and measure deposited energy over a large target volume make it ideal for precision neutrino physics measurements and searches for rare processes like proton decay. A dedicated effort is needed to calibrate these detectors. The LArIAT (Liquid Argon In A Testbeam) Experiment aims to characterize the response of a LArTPC to the particles often seen as final products of ~1 GeV neutrino interactions using a beam of particles with known momenta, produced from a high-energy pion beam at the Fermilab Test Beam Facility (FTBF). In Phase I of LArIAT, the ArgoNeuT cryostat was reused with a refurbished TPC of 170 liter active volume. It's unique in its use of cold readout electronics as well as its powerful light collection system, which uses PMTs to detect light from reflector foils coated in a thin layer of wavelength shifting tetraphenyl-boutadiene (TPB) mounted along the inner field cage walls of the TPC. Data-taking will run through the end of June, and the collected data will help in understanding electron recombination behavior, shower reconstruction, particle identification, muon sign determination, pion and kaon interactions in argon, and the use of scintillation light for calorimetry. The status of the data analysis from LArIAT’s Phase I run will be presented.

Speaker: William Foreman (University of Chicago)

15.08.04_DPF_LArIATRun1.pdf

54 The MicroBooNE Experiment and the Impact of Space Charge Effects

MicroBooNE is an experiment designed to both probe neutrino physics phenomena and develop the LArTPC (Liquid Argon Time Projection Chamber) detector technology. The MicroBooNE experiment, which begins data-taking this year, will be the first large LArTPC detector in the U.S. and second worldwide - an experiment that is the beginning of a path of detectors envisioned for the U.S. SBL (Short BaseLine) and LBL (Long BaseLine) programs. In order to interpret the data from these experiments, the impact of space charge effects must be simulated and calibrated. The space charge effect is the build-up of slow-moving positive ions in a detector due to, for instance, ionization from cosmic rays, leading to a distortion of the electric field within the detector. This effect leads to a displacement in the reconstructed position of signal ionization electrons in LArTPC detectors. The LArTPC utilized in the MicroBooNE experiment is expected to be modestly impacted from the space charge effect, with the electric field magnitude changing by roughly 5% (at a drift field of 500 V/cm) in some locations within the TPC. The flow of liquid argon within the detector may complicate matters even further. We discuss the simulation of the space charge effect at MicroBooNE as well as calibration techniques that make use of a UV laser system and cosmic muon events. A successful calibration of the space charge effect is imperative both to the success of the MicroBooNE physics program as well as to the development of LArTPC technology for future experiments.

Speaker: Michael Mooney

MicroBooNE_DPFtalk_15_08_04.pdf

55 Signal Processing in the MicroBooNE LAr TPC

The MicroBooNE experiment is a Liquid Argon Time Projection Chamber (LAr TPC) detector designed to observe interactions of neutrinos from the on-axis Booster and off-axis NuMI beams at the Fermi National Accelerator Laboratory. The detector consists of a 2.5m × 2.3m × 10.4m TPC including an array of 32 PMTs used for triggering purposes. The inner TPC is housed in an evacuable and foam insulated cryostat vessel. It has a 2.5m drift length in a uniform field of 500V/cm. There are 3 readout wire planes (U, V and Y coordinates) with 3mm pitch for a total of 8,256 signal channels. The fiducial mass of the detector is 60 metric ton of LAr. When primary electrons from an ionizing track drift to the detection wire planes along the electric field lines, small bipolar signals are induced on the U and V induction planes, and a large unipolar signal is induced on the collection Y plane. All current signals are processed and read out by the front end readout electronics. We present the process of converting the input raw digitized waveforms which are a convolution of detector field response, electronics response and noise to the deconvoluted signal (in charge and time). These ingredients are critical for the correct event reconstruction in the TPCs.

Speaker: Dr Jyoti Joshi (Brookhaven National Laboratory)

DPF_08042015.pdf

56 The CAPTAIN experiment

The Cryogenic Apparatus for Precision Tests of Argon Interactions with Neutrinos (CAPTAIN) program isdesigned to make measurements of scientific importance to long-baseline neutrino physics and physics topics that will be explored by large underground detectors. The experiment employs two liquid Argon time projections chambers (LArTPCs), – a primary detector with approximately 10-ton that will be deployed at different facilities for physics measurements and a prototype detector with 2-ton of liquid argon for configuration testing. The physics programs for CAPTAIN include measuring neutron interactions at Los Alamos Neutron Science Center, measuring neutrino interactions in medium energy regime (1.5–5 GeV) at Fermilab's NuMI beam, and measuring neutrino interactions in low energy regime (< 50 MeV) at stopped pion sources for supernova neutrino studies. This talk will give an overview of the status of the CAPTAIN program.

Speaker: Jianming Bian (University of Minnesota)

Captain_DPF2015_08_01.pdf

EWK and Higgs Sector: Higgs Properties - CP

Convener: Marc Sher (William and Mary College)

57 Study of the spin and parity of the Higgs boson in di-boson decays with the ATLAS detector

This talk will present studies of the spin, parity and tensor couplings of the Higgs boson in the H → ZZ* → 4l, H → WW* → eνµν and H → γγ decay processes at the LHC, based on 25 fb^-1 of pp collision data collected by the ATLAS experiment at 7 TeV and 8 TeV. The Standard Model (SM) Higgs boson hypothesis, corresponding to the quantum numbers J^P = 0⁺, is tested against several alternative spin scenarios, including non-SM spin-0 and the spin-2 models with universal and non-universal couplings to fermions and vector bosons. Using the H → ZZ* → 4l and H → WW* → eνµν decays, the tensor structure of the HVV interaction in the spin-0 hypothesis is also investigated.

Speaker: Nan Lu (University of Michigan (US))

SpinCP_Combination_DPF_2015_NanLu.pdf

58 Tools for the Higgs boson CP studies: JHUGen and MELA

In this talk we discuss the MC simulation (JHUGen) and analysis tools based on matrix element approach (MELA) to study the extent to which CP parity of a Higgs boson H(125), and more generally its anomalous couplings to gauge bosons and fermions, can be measured in Run2 of LHC. We consider several production processes, including Higgs boson production in gluon and weak boson fusion and production of a Higgs boson in association with an electroweak gauge boson or heavy-flavor quarks. Both on-shell and off-shell production of the H(125) boson are considered. In the study of decay kinematic correlations, we consider decays of a Higgs boson to ZZ, Zgamma, gamma gamma, and WW, with either real or virtual bosons.

Speaker: Heshy Roskes (Johns Hopkins University (US))

JHUGen.pdf

59 125 GeV Higgs signal at the LHC in the CP-violating MSSM

The ATLAS and CMS collaborations independently discovered a Higgs-like particle with mass $M_h \sim$ 125 GeV and properties similar to that predicted by the Standard Model (SM) at the Large Hadron Collider (LHC) in 2012. Although the measurements so far indicate that the newly discovered particle is compatible with the SM predictions, however due to some uncertainties in few of the Higgs detection channels, there are still possibilities of testing this object as being a candidate for some Beyond the SM (BSM) physics scenarios, for example, the CP-conserving Minimal Supersymmetric Standard Model (CPC-MSSM). Moreover there are unsettled issues like the hierarchy problem, which add more objectives to go for the BSM scenarios. In the present work, we evaluate the modifications of these CPC-MSSM results when CP-violating (CPV) phases are introduced explicitly, leading to the CP-violating MSSM (CPV-MSSM). We investigate the role of the CPV phases of (some of) the soft Supersymmetry (SUSY) terms (viz., the gluino mass $M_1$ and the trilinear Higgs couplings with the sfermions $A_f, f=t,b,\tau$) on both the mass of the lightest Higgs boson $h_1$, and the rates for the processes $gg \rightarrow h_1 \rightarrow \gamma \gamma$, $gg \rightarrow h_1 \rightarrow ZZ^*\rightarrow 4l$, $gg \rightarrow h_1 \rightarrow WW^*\rightarrow l \nu l \nu$, $pp \rightarrow V h_1 \rightarrow V b\bar b$ and $pp \rightarrow V h_1 \rightarrow V \tau^+\tau^-$, ($V \equiv W^\pm, Z$) at the LHC, considering the impact of the flavor constraints as well as the stringent constraints coming from the Electric Dipole Moment (EDM) measurements for the electron, neutron, Thallium and Mercury. We find that it is possible to have the lightest Higgs boson mass of around 125 GeV with relatively small $\tan\beta$, large $A_t$ and a light stop, which is consistent with the SUSY particle searches at the LHC. We show that the imaginary part of the top and bottom Yukawa couplings can take small but non-zero values even after satisfying the recent updates from both the ATLAS and CMS collaborations within 1-2$\sigma$ uncertainties which might be a stong signature of the CP violation to look for at the future run of the LHC. Our analysis shows that the CPV-MSSM could be an equally potent solution (like the CPC-MSSM) to the recent LHC Higgs data, in fact offering very little in the way of distinction between these two SUSY models (CPC-MSSM and CPV-MSSM) at the 7 and 8 TeV run of the LHC. Improvement in different Higgs coupling measurements is necessary in order to test the possibility of probing the small dependence on these CPV phases in the MSSM Higgs sector.

Speaker: Mr Biswaranjan Das (Indian Institute of Technology Guwahati, India)

Quark and Lepton Flavor Physics

Conveners: J Michael Williams (Massachusetts Inst. of Technology (US)), Jure Zupan (University of Cincinnati)

60 Test of lepton universality in the ratio of branching fractions BF(Y(3S)-> tau+tau-)/BF(Y(3S)->mu+mu-) at BABAR

61 Search for $B^{0}\rightarrow l^+ l^-$ at Belle

The decay modes $B^0 \rightarrow \ell^{+} \ell^-$ where $\ell = e$ or $\mu$ are a group of very rare particle decays with vanishingly small branching fractions. To date, no experimental verification of the branching fractions has been found. Observation of such decays could show clear evidence of new physics such as the Higgs doublets (for $B \rightarrow e^+e^-$ or $B \rightarrow \mu^+\mu^-$) or lepton-nonconserving interactions (for $B \rightarrow e^{\pm}\mu^{\mp}$). Using the full set of Belle experimental data with over $700$ fb$^{-1}$ collected at the $\Upsilon(4S) $ resonance, we present a study of the rare decay $B^0 \rightarrow \ell^{+} \ell^-$.

Speaker: Kimberly Williams

DPF_b2ll.pdf

62 Study of CP asymmetry in B0-B0bar mixing using inclusive dilepton samples in BABAR

The asymmetry between same sign inclusive dilepton samples (l+l+ and l-l-) from semileptonic B decays in Upsilon(4S) -> B0 B0bar events allows us to compare B0 mixing probabilities P(B0bar -> B0) and P(B0 -> B0bar), and therefore to test the T and CP invariance. We present the measurement of CP asymmetry in inclusive dilepton samples with the full BABAR dataset near the Upsilon(4S) resonance, corresponding to 471 million BBbar pairs.

Speaker: Tomonari Miyashita

Miyashita.pdf

63 Searching for Nucleon Decay with Super-Kamiokande

Speaker: Edward Kearns (Boston University)

kearns-DPF-SK-pdk.pdf

64 The Mu2e Experiment at Fermilab

Speaker: Marc Buehler (Fermi National Accelerator Laboratory)

DPF2015_Mu2e_v3.pptx

BSM Physics

Conveners: Kevin Black (Boston University), Nathaniel Craig (UC Santa Barbara), Rouven Essig

65 Estimating QCD background in search for new physics in events with missing energy and large hadronic activity in pp collisions at 13 TeV

We present a method for predicting the Quantum Chromodynamics (QCD) background in a search for Supersymmetry (SUSY) at the Compact Muon Solenoid (CMS) experiment based on events with large missing energy, large hadronic activity and zero or more identified bottom quark jets. This signature arises in so-called natural SUSY models and is expected to be accessible at the center-of-mass energy of 13 TeV proton-proton collisions at CERN’s Large Hadron Collider (LHC). The study is based on simulated Monte Carlo (MC) events. We describe in detail the use of a QCD control region parallel to the signal region and the technique used to extrapolate from the QCD dominated control region to the signal region.

Speaker: Pawandeep S Jandir (University of California Riverside (US))

dpf_jandir_v3.pdf

66 Search for Displaced Supersymmetry in Events with an Electron and a Muon with Large Impact Parameters

A search for new long-lived particles decaying to leptons is presented using proton-proton collisions produced by the LHC at sqrt(8)  TeV. Data used for the analysis were collected by the CMS detector and correspond to an integrated luminosity of 19.7 /fb. Events are selected with an electron and muon with opposite charges that both have transverse impact parameter values between 0.02 and 2 cm. The search has been designed to be sensitive to a wide range of models with nonprompt electron-muon final states. Limits are set on the “displaced supersymmetry” model, with pair production of top squarks decaying into an electron-muon final state via R-parity-violating interactions. The results are the most restrictive to date on this model, with the most stringent limit being obtained for a top squark lifetime corresponding to ctau = 2  cm, excluding masses below 790 GeV at 95% confidence level.

Speaker: Jamie Antonelli (The Ohio State University (US))

Antonelli_DPF2015_DisplacedSUSY.pdf

67 Search for Chargino and Neutralino using Two Jets in Vector-Boson-Fusion Topology at CMS

Vector Boson Fusion (VBF) tagging is an interesting 
and promising new avenue to probe difficult models such as the compressed electroweak and 
colored spectra scenarios in supersymmetry (SUSY). A search of SUSY using the VBF topology is presented using 19.7 fb-1 
of data from pp collisions at 8 TeV collected by the CMS detector. Focus is placed on SUSY models that have significant branching fractions to leptons, resulting in final states with at least two 
reconstructed leptons with like-sign or opposite-sign electric charge. The number of observed events 
are consistent with the standard model expectations. Limits on the chargino and neutralino masses at 
95 % confidence level are set.

Speaker: Carlos Andres Florez Bustos (Universidad de los Andes (CO))

DPF2015_AndresFlorez.pdf

68 Search for direct scalar top production with R-Parity Violating decay in pp collisions at sqrt(s)=8 TeV with ATLAS

A search is presented for direct scalar top pair production, where the scalar tops decay via an R-parity-violating coupling to a final state with two leptons and two identified b jets. The analysis uses 20.3 fb−1 of sqrt(s)= 8 TeV proton-proton collision data collected with the ATLAS detector at the LHC. No significant excess is observed over the Standard Model background. Assuming a supersymmetric minimal B−L extension to the Standard Model, limits on the scalar top mass are placed between 500 GeV and 1 TeV with a branching fraction above 20% for the scalar top to decay to an electron or a muon and a b-quark.

Speaker: Evelyn Jean Thomson (University of Pennsylvania (US))

2015-dpf-thomsone-final-r1.pdf

69 Searches for RPV SUSY via LQD couplings at CMS Experiment

Unlike the most traditional SUSY searches, there exist many SUSY models that do not produce large missing transverse momentum (MET), such as compressed spectra, long live particles, stealth SUSY, and R-parity violating (RPV) models. Searches for RPV model via the LQD couplings have been performed at CMS experiment, using LHC Run I data, in event signatures of two opposite sign same flavor dileptons (electrons, muons, taus), and at least two or five jets, and low MET. No top squarks were observed during Run I, and the most recent limits for these channels will be presented. A first look at searches at the LHC Run II will be also shown.

Speaker: Sadia Khalil (Kansas State University (US))

DPF2015_RPVSUSY_SadiaKhalil.pdf

70 Exploration of Physics Beyond the Standard Model at the International Linear Collider

Although the LHC experiments have put strong limits on coloured supersymmetric states, it is still possible that electroweakly interacting supersymmetric particles have masses in the range 100-200 GeV. Even outside of supersymmetry, candidates for the particle of dark matter may have masses in this range unconstrained by LHC data. In e+e- annihilation, the low backgrounds, precise knowledge of the initial-state beams, and sensitivity to small energy depositions provides discovery potential complementary to the LHC, for instance in cases with small mass differences. These conditions are also ideal for the precise measurements of new particle states required to elucidate the structure of the underlying model in scenarios where colored sparticles are discovered during the 14 TeV run of the LHC, which could hint to the existence of lower-mass electroweak states. This contribution will report the current status of studies for the prospects of measurements of WIMPs, Higgsinos and other light electroweak states at the International Linear Collider, with results based on simulation of the detectors proposed for the ILC. It also discusses how the combined observations from LHC and ILC can be used to determine MSSM parameters in models with large numbers of free parameters.

Speaker: Stefania Gori

TalkDPF.pdf

71 Producing Heavy Squarks at 100 TeV

If Supersymmetry is realized in nature, there are both theoretical and phenomenological reasons to believe that the masses of scalar superpartners to the quarks (squarks) lie in the tens of TeV range. This renders squark pair production kinematically out of reach for both LHC-14 and 100 TeV future hadron colliders. In this talk, I will instead discuss the associated production of a heavy squark along with superpartners to gauge bosons (gauginos) at a 100 TeV collider. This channel provides a powerful probe of the heavy squark parameter space, and can even be the discovery mode for Supersymmetry. Using a simple set of kinematic cuts, I will show that for gaugino masses in the multi-TeV range, squarks with masses up to 30 TeV can be discovered at a 100 TeV collider with sufficient luminosity.

Speaker: Mr Bob Zheng (University of Michigan)

DPFtalk-BZheng.pdf

72 Prospects for a Search for Z' to the Dimuon Final State in Run 2 of the LHC

I will report the physics potential for a search for a new, non-Standard Model gauge boson, Z’, in its decay to the dimuon final state in Run 2 of the Large Hadron Collider, using the ATLAS detector. Detection of high transverse momentum muons is crucial for the search. A first look at the performance of high transverse momentum muons using early Run 2 data at 13 TeV center-of-mass energy will be reported.

Speaker: Yanlin Liu (Univ. of Michigan (US) / Univ. of Sci. & Tech. of China (CN))

DPF2015-Yanlin.pdf

73 A First Look at 13 TeV Data for the Exotic Dilepton Channel Search using the ATLAS Detector

With the increase of centre of mass energy from 8 to 13 TeV, Run-2 at the LHC is a very exciting time for searches beyond the standard model. The search for resonant and non-resonant new phenomena in the dilepton channel has the potential to make a discovery very quickly during this period. This talk presents a very first look at 13 TeV data, using the Run-2 event selection for this search, though a search is not yet performed due to the relatively low integrated luminosity.

Speaker: Daniel Hayden (Michigan State University (US))

Hayden_DileptonSearch_DPF.pdf

LHC Run-2 Detector Performance

Conveners: Anyes Taffard (University of California Irvine (US)), Petra Merkel (Fermi National Accelerator Lab. (US))

74 Novel real-time calibration & alignment and tracking performance for LHCb Run II

The LHCb detector consists of subsystems designed to perform high efficiency track reconstruction (> 95%) with an excellent momentum resolution (0.5% for p< 20 GeV). Two Ring Imaging Cherenkov detectors provide particle identification with a high precision. In Run II of the LHC, a new scheme for the software trigger at LHCb allows splitting the triggering of the event in two stages, giving room to perform the alignment and calibration in real time. In the novel detector alignment and calibration strategy for Run II, data collected at the start of the fill are processed in a few minutes and used to update the alignment, while the calibration constants are evaluated for each run. This allows identical constants to be used in the online and offline reconstruction. The larger timing budget, available in the trigger, results in the convergence of the online and offline track reconstruction. The same performance of the track reconstruction and PID are achieved online and offline. This offers the opportunity to optimise the event selection in the trigger with stronger constraints and including the hadronic PID. It additionally increases selection efficiencies and purity and reduces systematic uncertainties. The novel real-time alignment and calibration strategy at LHCb is discussed from both the operational and physics performance points of view. The development and improvements in the track reconstruction are highlighted. The overall performances of the LHCb detector on the first data of Run II are presented.

Speaker: Espen Eie Bowen (Universitaet Zuerich (CH))

DPF-2015-Tracking-Bowen.pdf

75 The CMS Beam Halo Monitor Detector System

A new Beam Halo Monitor (BHM) detector system has been installed in the CMS cavern to measure the machine-induced background (MIB) from the LHC. This background originates from interactions of the LHC beam halo with the final set of collimators before the CMS experiment and from beam gas interactions. The BHM detector uses the directional nature of Cherenkov radiation and event timing to select particles coming from the direction of the beam and to supress those originating from the interaction point. It consists of 40 quartz rods, placed on each side of the CMS detector, coupled to UV sensitive PMTs. For each bunch crossing the PMT signal is digitized by a charge integrating ASIC and the arrival time of the signal is recorded. The data are processed in real time to yield a precise measurement of per-bunch-crossing background rate. This measurement is made available to CMS and the LHC, to provide real-time feedback on the beam quality and to improve the efficiency of data taking. In this talk we will describe the detector system, its operation and present the first results obtained in Run II.

Speaker: Kelly Marie Stifter (University of Minnesota (US))

Presentation_APS.pdf

Presentation_APS.pptx

76 Improvements to ATLAS track reconstruction for Run-2

Run-2 of the LHC will provide new challenges to track and vertex reconstruction with larger energies, denser jets and higher rates. We will discuss performance enhancements due to the Insertable B-layer (IBL), a fourth pixel layer which has been added to the innermost part of the ATLAS detector. We will also discuss improvements to the track reconstruction developed during the two year shutdown of the LHC. These include novel techniques which improve the tracking performance in the dense cores of jets, optimization for the expected conditions, and an extended software campaign which has lead to a factor of three decrease in the CPU demands for each recorded event. The commissioning of the detector in preparation for Run-2 using cosmic data and early collision data will also be discussed.

Speaker: Michael Ryan Clark (Columbia University (US))

clark_atlas_indet_run2.pdf

77 The performance and development of the Inner Detector Trigger Algorithms at ATLAS for LHC Run 2

A description of the design and performance of the newly reimplemented tracking algorithms for the ATLAS trigger for LHC Run 2, to commence in spring 2015, is provided. The ATLAS High Level Trigger (HLT) has been restructured to run as a more flexible single stage process, rather than the two separate Level 2 and Event Filter stages used during Run 1. To make optimal use of this new scenario, a new tracking strategy has been implemented for Run 2 for the HLT. This new strategy will use a Fast Track Finder (FTF) algorithm to directly seed the subsequent Precision Tracking, and will result in improved track parameter resolution and significantly faster execution times than achieved during Run 1 but with no significant reduction in efficiency. The performance and timing of the algorithms for numerous physics signatures in the trigger are presented. The profiling infrastructure, constructed to provide prompt feedback from the optimisation, is described, including the methods used to monitor the relative performance improvements as the code evolves. The online deployment and commissioning, together with the first measurements with the Run 2 data are also discussed.

Speaker: Benjamin Sowden (Royal Holloway, University of London)

15-08-04 - DPF.pdf

78 Commissioning and Alignment of the Pixel Luminosity Telescope of CMS

The Pixel Luminosity Telescope (PLT) is one of the newest additions to the CMS detector at the LHC. It consists of 16 3-layer telescopes of silicon pixel detectors pointing toward the interaction point at the center of CMS. The pixel detectors are based on the same technology as the silicon pixel detector of CMS. The chips have an additional output, called a fast-out. This fast-out is sent whenever a hit is detected, and will be used to measure the luminosity. The fast-out can also be used to self trigger the PLT allowing for measurement of the systematics and beam backgrounds. The PLT is expected to significantly improve the precision of the luminosity measurement that is fundamental for particle searches and cross section measurements with the CMS detector. Furthermore, with reconstructed particle trajectories, measurements of beam backgrounds and the location of the interaction point centroid can be obtained. First experiences with the PLT detector before and after installation are presented and first results and tracks from unstable collisions in the LHC are discussed.

Speaker: Grant Riley (University of Tennessee (US))

DPF-GrantRiley-PLT_long.pdf

Accelerators, Detectors, Computing

Conveners: Michael Aaron Kagan (SLAC National Accelerator Laboratory (US)), Toyoko Orimoto (Northeastern University (US))

79 Pilot System for the CMS Phase I Pixel Upgrade

The Pilot Blade System, now installed in the CMS Pixel Detector, is a first test of the new technologies to be used in the CMS Phase I Pixel Detector. The Phase I Pixel will have twice the number of readout channels and a faster, digital data transmission. The Pilot Blade System contains two assemblies each with four Phase I modules mounted on two blades. One assembly was installed in each endcap of the current Pixel Dector during the last shutdown. The Pilot Blade System will allow for the testing of the new readout electronics, powering system, and online software in the actual operational environment. A report on the initial system tests and performance during the first operation of the system will be given.

Speaker: Robert Stringer (University of Kansas (US))

DPF2015-PilotBlade.pdf

80 Studies on the prototype of ATLAS Phase-2 pixel module

The Phase-2 upgrade of the ATLAS Inner Tracker (ITk) will serve as replacement of the current Inner Detector and cope with more challenging experimental conditions at the High Luminosity LHC (HL-LHC). In this talk, I summarize studies done on the prototype of the ATLAS Phase-2 pixel module, which will be used for the barrel and high-eta region of ITk.

Speaker: Hongtao Yang (University of Wisconsin (US))

quad_module_stavelet_hongtao.key

quad_module_stavelet_hongtao.pdf

81 Radiation-Hard/High-Speed Parallel Optical Engine

The LHC has recently been upgraded to operate at higher energy and luminosity. In addition, there are plans for further upgrades. These upgrades require the optical links of the experiments to transmit data at much higher speed in a more intense radiation environment. For the recently completed upgrade, we designed a new radiation-hard/high-speed parallel optical engine for the upgraded pixel detector of ATLAS. The new fiber optic transceivers, opto-boards, were designed to replace the first generation opto-boards installed on the pixel detector and for the new pixel layer. Each opto-board contains one 12-channel PIN array and two 12-channel VCSEL arrays along with associated receiver/driver ASICs. The new opto-board design benefits from the production and operational experience of the first generation opto-boards and contains several improvements. The new opto-boards have been installed. We will present the design, production and operational experience, and reliability study of the new opto-boards. For the future upgrade, we have designed an ASIC that contains four high-speed/radiation-hard drivers to operate an array of four VCSELs at 10 Gb/s. The ASIC has been fabricated in a 65 nm CMOS process. We have also designed a new opto-board that couples an ASIC to a VCSEL array. For the future, we plan to increase the number of channels to twelve. We will present the result from the new high-speed optical engine together with the future plan.

Speaker: K.K. Gan (The Ohio State University (US))

DPF2015)_Gan.pdf

82 A Cosmic Ray Veto Detector for the Mu2e Experiment at Fermilab

The Mu2e experiment is designed to search for the charged-lepton-flavor-violating process, $\mu^-$ to a $e^-$, with unprecedented sensitivity. The single 105-MeV electron that results from this process can be mimicked by electrons produced by cosmic-ray muons traversing the detector. An active veto detector surrounding the apparatus is used to detect incoming cosmic-ray muons. To reduce the backgrounds to the required level it must have an efficiency of about 99.99% as well as excellent hermeticity. The detector consists of four layers of scintillator counters, each with two embedded wavelength-shifting fibers, whose light is detected by silicon photomultipliers. The design and expected performance of the cosmic ray veto detector will be described.

Speaker: Prof. E. Craig Dukes (University of Virginia)

DPF2015_CRV_Overview.pdf

83 Performance of Scintillation Counters with Silicon Photomultiplier Readout

The performance of scintillator counters with embedded wavelength-shifting fibers have been measured in the Fermilab Meson Test Beam Facility using 120 GeV protons. The counters were extruded with a titanium dioxide surface coating and two channels for the fibers at the Fermilab NICADD facility. Each fiber end is read out by a $2{\times}2$ mm$^2$ silicon photomultiplier. The signals were amplified and digitized by a custom-made front-end electronics board. Extrusions with $5{\times}2$ cm$^2$ and $6{\times}2$ cm$^2$ profiles were tested, and with 1.4 and 1.8 mm diameter fibers. The design is intended to be used in the cosmic-ray veto detector for the Mu2e experiment at Fermilab. The time response and light yield as a function of the transverse and longitudinal position within the counters, as well as incident beam angle, will be given.

Speaker: Mr Yongyi Wu (University of Virginia)

DPF_presentation_final.pdf

84 Radiation Damage Testing of Silicon Photomultipliers for the Mu2e Experiment

The Mu2e experiment at Fermilab will be looking for charged lepton flavor violation by searching for muon-to-electron conversion. A critical element of the detector for identifying and rejecting background events will be the cosmic ray veto (CRV) comprised of scintillator strips using wavelength-shifting (WLS) fibers mated to silicon photomultipliers (SiPMs). The CRV will cover approximately 325 sq. meters, use ~20K SiPMs and be subjected to an integrated dose of ~5E9 neutrons (1 MeV equivalent) per sq. cm over the life of the experiment. As part of the campaign to identify devices that best serve the purposes of the CRV we report on radiation damage studies for SiPMs from several vendors by monitoring performance measures like dark current, dark rate, single photo-electron resolution, cross-talk, after-pulsing and response before and after exposure to proton and neutron radiation.

Speaker: Dr Vishnu Zutshi (Northern Illinois University)

VZ_DPF_v0-1.pdf

85 Beam Test Results of the Dependence of Signal Size on Incident Particle Rate in Diamond Pixel and Pad Detectors

For two decades the CERN-based RD42 collaboration has investigated Chemical Vapor Deposition (CVD) diamond as a radiation tolerant alternative for precision tracking detectors. I will present beam test results of charged particle detectors based on single-crystal and poly-crystalline CVD diamond. The detectors were tested over a range of particle fluxes from 2 kHz/cm^2 to 2 MHz/cm^2. The pulse height of the sensors was measured with pad and pixel readout electronics. The pulse height of the non-irradiated single-crystal CVD diamond sensors was stable with respect to flux, while the pulse height of irradiated single-crystal CVD diamond sensors decreased with increasing particle flux. The observed sensitivity to flux is similar in both the diamond pad sensors constructed using diamonds from the Pixel Luminosity Telescope (PLT) irradiated during its pilot run in CMS detector and in neutron irradiated diamond pad sensors from the same manufacturer irradiated to the same fluence of neutrons. The pulse height for irradiated poly-crystalline CVD diamond pad sensors proved to be stable with respect to particle flux. This work will be extended this summer with rates up to 20MHz/cm^2 in both polycrystalline and single-crystal CVD diamond. The results from the latest beam tests of the dependence of signal size on incident particle rate in charged particle detectors based on single-crystal and poly-crystalline CVD diamond will be shown.

Speaker: Bin Gui (Ohio State University (US))

DPF2015_BinG_v5.pdf

86 The qualification of the forward pixel detector modules for the CMS phase 1 upgrade

The phase 1 upgrade of the CMS pixel detector will replace the existing pixel detector at the end of 2016 in an extended technical stop. The phase 1 upgrade includes four barrel layers and three forward disks, providing robust tracking and vertexing for LHC luminosities up to 2.5 x 10^34 cm-2 s-1 prior to the HL-LHC era. The upgrade incorporates new readout chips and front-end electronics for higher data rates, DC-DC powering, and dual-phase CO2 cooling to achieve performance exceeding that of the present detector with a lower material budget. The design of the forward detector is presented along with present status of mechanical construction, module assembly, and module qualification. The procedures for module testing and quality assurance are described in some detail.

Speaker: Jamie Antonelli (The Ohio State University (US))

Antonelli_DPF2015_FPixModuleTesting.pdf

QCD and Heavy Ions

Convener: Radja Boughezal (Argonne National Laboratory)

QCDTevDPF2015.pdf

87 Recent Jet Substructure Results from the LHC

Recent Jet Substructure Results from the ATLAS and CMS experiments.

Speaker: Ben Nachman (SLAC National Accelerator Laboratory (US))

Nachman_QCDResults_DPF2015.pdf

88 PDF Overview

Speaker: Tie-Jiun Hou (SMU)

2015.0804_DPF2015.pdf

89 Mathematica Toolbox for PDF Uncertainties and Application to New Physics Searches

As the LHC begins Run 2 at an even higher energy, one of the top priorities will be to search for new particles (SUSY, …) at the highest energy scales. In addition to direct production of new particles, they can mix with Standard Model (SM) particles to yield discrepancies from the usual predictions. To distinguish this new physics from old uncertainties, we need tools to easily quantify the uncertainties of the SM predictions. Here we present a versatile set of utility functions built with Mathematica that is capable of working with a variety of PDF formats including the recent LHAPDF6 format. This software can perform PDF calculations within the Mathematica framework and compare results from different PDF collaborations. The package includes both the central PDF value as well as the full error sets needed for PDF uncertainty analysis; a variety of sample error definitions are implemented. We demonstrate this package for the case of a new heavy scalar particle production at the LHC.

Speaker: Eric Godat (Southern Methodist University)

DPF_8_2_15.pdf

90 Vector boson production in association with jets and heavy flavor quarks at CMS

The production of vector bosons (V = W, Z) in association with jets is a stringent test of perturbative QCD and is a background process in searches for new physics. Total and differential cross-section measurements of vector bosons produced in association with jets and heavy flavour quarks in proton-proton collisions performed by the CMS collaboration at the LHC are presented. The measurements are compared to the predictions of event generators and theoretical calculations at next-to-leading order.

Speaker: Emanuela Barberis (Northeastern University, CMS Collaboration)

VJets-DPF-Barberis.pdf

VJets-DPF-Barberis.pptx

91 Drell-Yan Production of W/Z at the LHC with Protons and Heavy Nuclei

Drell-Yan W/Z electroweak boson production at the LHC is an essential standard candle which is used for calibration of beam luminosity and detector properties. In addition to proton-proton collisions, the LHC has measured heavy nuclei lead-lead and proton-lead W/Z production. Comparison of these data sets can provide discriminating information of the nuclear modifications present in the Parton Distribution Functions (PDFs). We present an analysis of W/Z production in lead-lead and proton-lead collisions at the LHC using the nCTEQ15 nuclear Parton Distribution Functions (nPDFs) including the uncertainty bands. The cross-sections are calculated at NLO with the FEWZ program at 2.76 and 5.02 TeV. We identify observables where the nuclear modifications are larger than the predicted uncertainty, and we compare these calculations to recent CMS measurements.

Speaker: David Clark (Southern Methodist University)

clarkDPF_2015.pdf

Top Physics

92 Run-1 Single-top measurements at CMS

The Run-1 of the LHC was very successful for single top physics in CMS. The main single top production mode, t-channel, is well established. The t-channel cross-section was measured with unprecedented precision and t-channel events have been used for the first time to perform measurement of SM properties, such as: |Vtb|, top quark polarization, or W-helicity fractions. The associated production with a W boson, tW, has a large cross section at the LHC and has been observed by CMS for the first time. Finally, the s-channel also has been studied and limits set

Speaker: Rebeca Gonzalez Suarez (University of Nebraska (US))

DPF.pdf

93 Recent results on top-quark physics at D0

We present the most recent measurements on top-quark physics obtained with Tevatron $p \bar p$ collisions recorded by the D0 experiment at $\sqrt s=1.96$ TeV. The full Run II data set of 9.7 fb$^{-1}$ is analyzed. Both lepton+jets and dilepton channels of top-quark pair production are used to measure the differential and inclusive cross-sections, the forward-backward asymmetries, the top-quark mass, the spin correlations, and the top-quark polarization.

Speaker: Kenneth Bloom (University of Nebraska (US))

dpf_d0top_15080X.pdf

94 b,c-tagging, W+jet, and top measurements with LHCb

Excellent vertexing, tracking, and jet energy resolution enable a variety of forward analyses to be performed using data from the LHCb detector. Recent results on the performance of inclusive b and c-tagging algorithms used by LHCb are presented. These taggers are applied to W+jet data to measure W+b-jet and W+c-jet asymmetries as well as ratios to inclusive W+jet production. Additionally, the first forward observation of top using Run I LHCb data is shown.

Speaker: Philip Ilten (Massachusetts Inst. of Technology (US))

ilten.pdf

95 Top Quark Physics at a Future Linear Collider

The International Linear Collider and Compact Linear Collider projects aim to build a linear electron-positron collider with a center-of-mass energy well above the top quark pair production threshold. In this contribution an overview is presented of the potential of their top quark precision physics programme. One of the highlights is a precise determination of the top quark mass through a scan of the center-of-mass energy around the pair production threshold, that is expected to yield a total uncertainty on the top quark MSbar mass of less than 50 MeV. The results of a full-simulation analysis are presented, including a discussion of the main systematic uncertainties. Full simulation results are also presented for measurements of the top quark couplings to the Z-boson and the photon are presented. The anomalous form factors are expected to be constrained to better than 1%, significantly beyond the expected precision at the Large Hadron Collider. Further new results are presented for the sensitivity to non-standard top quark decays and its interaction with the Higgs boson.

Speaker: Graham Wilson (University of Kansas (US))

LCC_Top-Physics_V2.pdf

19:00 Reception and Posters

Wednesday 5 August

07:30 Breakfast

Session I-B

Convener: Bing Zhou (University of Michigan (US))

96 Top Physics

Recent results on top quark properties and interactions are presented, obtained using data collected at the LHC and Tevatron. Measurements are performed for the inclusive and differential top quark pair production cross sections in several top quark final states. The mass of the top quark is extracted using several methods, including indirect constraints from the measured cross section. Cross sections for the electroweak production of single top quarks are measured in several channels. Further results include measurements of top quark properties, such as the W helicity in top decays, the top pair charge asymmetry, the top quark polarization as well as the search for anomalous couplings in both pair and single top-quark production. All results are compared with predictions from the standard model.

Speaker: Kevin Patrick Lannon (University of Notre Dame (US))

DPF2015-08-05_TopPhysics.pdf

97 Latest Electroweak Results

I will focus on the latest electroweak results obtained from ATLAS and CMS experiments, and talk about precision measurements to determine fundamental parameters; also studies with diboson, triboson and vector boson scattering final states.

Speaker: Junjie Zhu (University of Michigan (US))

DPF_EWK_Zhu.pdf

98 Higgs Physics: Highlights from the Post-Discovery Era

The discovery in 2012 of a Higgs boson at the ATLAS and CMS experiments was a pivotal moment in the decades-long pursuit of understanding the mechanism behind electroweak symmetry breaking. The focus of subsequent studies at the LHC has been the characterization of this recently-discovered particle through precision measurements of its couplings, spin, width and other properties. This characterization campaign is crucial in understanding whether this Higgs boson is consistent with the predictions of the standard model or a harbinger of new physics. Further, direct searches for exotic Higgs production mechanisms or rare Higgs decays could reveal yet-unseen dynamics that are important for understanding the remaining open questions in particle physics. In this talk I will summarize the state of Higgs physics from the experimental perspective, focusing mostly on results from the LHC Run 1 and with an eye towards what could be in store in Run 2.

Speaker: Christopher Neu (University of Virginia (US))

neu_Higgs_v2.pdf

10:15 Cafe Break

Session II-B

Convener: Kenneth Bloom (University of Nebraska (US))

99 Lattice QCD at the particle frontiers

I will discuss progress and prospects of using lattice QCD methods to address topics of current and future relevance to the global high-energy physics program. In particular, I will focus on the hadronic contributions to muon (g-2), flavour physics for LHC and Belle-II, and potential QCD inputs for the long-baseline neutrino program and for future precision Higgs measurements at a linear collider.

Speaker: William Detmold (Massachusetts Institute of Technology)

DPF-2015.pdf

100 Advancing the Era of Quantitative QCD: Experiment

With rapid theoretical progress in QCD ongoing since the mid-1990s, experiment and theory have been pushing forward hand-in-hand, with theoretical advances allowing more and more to be learned from the wealth of experimental data, while novel experimental results in turn inspire new theoretical ideas. As various subfields in QCD have advanced and evolved, new questions and directions have arisen at the frontiers, and some research areas that were once disparate have started to converge. A snapshot of some recent experimental results and the outlook for continuing to confront the challenges and surprises of strong interactions will be presented.

Speaker: Prof. Christine Aidala (University of Michigan)

AidalaDPF2015.pdf

101 Sculpting the BSM landscape with low-energy precision physics

The SM cannot explain the origin of the weak scale, nor the origin of dark matter, nor the cosmic surfeit of baryons. The answers to these and other questions could conceivably come from new physics at either high energy --- or low energy, through mixing with an as yet undetected hidden sector. I will draw a suite of examples from the precision frontier, including the g-2 of the muon and searches for permanent EDMs, rare decays, and neutron-antineutron oscillations, to show how they, taken in aggregate, can speak to a bigger picture.

Speaker: Susan Gardner (University of Kentucky)

svg_lowE_BSM_dpf15.pdf

12:30 Lunch

Trends in Physics Teachings

DOE Program: Detector R&D, Intensity Frontier

Conveners: Alan Stone (DOE), Glen Crawford (DOE)

102 Detector R&D

Speaker: Dr Glen Crawford (DOE)

DPF_2015_IFDetector_August2015_v2.pdf

AstroParticle, Cosmology, Dark Matter Searches, and CMB

Convener: Rachel Mandelbaum (Carnegie Mellon University)

103 Bound on the variation in the fine structure constant implied by Oklo data

Dynamical models of dark energy can imply that the fine structure constant $\alpha$ varies over cosmological time scales. Data on shifts in resonance energies $E_r$ from the Oklo natural fission reactor have been used to place restrictive bounds on the change in $\alpha$ over the last 1.8 billion years. We review the uncertainties in these analyses, focusing on corrections to the standard estimate of $k_\alpha\!=\!\alpha\,dE_r/d\alpha$ due to Damour and Dyson. Guided, in part, by the best practice for assessing systematic errors in theoretical estimates spelt out by Dobaczewski et al. [in J. Phys. G: Nucl. Part. Phys. 41, 074001 (2014)], we compute these corrections in a variety of models tuned to reproduce existing nuclear data. Although the net correction is uncertain to within a factor of 2 or 3, it constitutes at most no more than 25\% of the Damour-Dyson estimate of $k_\alpha$. Making similar allowances for the uncertainties in the modeling of the operation of the Oklo reactors, we conclude that the relative change in $\alpha$ since the Oklo reactors were last active (redshift $z\simeq 0.14$) is less than $\sim 10$ parts per billion. To illustrate the utility of this low-$z$ bound, we consider its implications for the string-inspired runaway dilaton model of Damour, Piazza and Veneziano.

Speaker: Ms Leila HAMDAN (Kuwait University)

OkloDPF2015.pdf

104 SPT-3G: The Next Generation Receiver for Polarized Cosmic Microwave Background Measurements with the South Pole Telescope

The South Pole Telescope is a millimeter-wavelength telescope dedicated to observations of the Cosmic Microwave Background (CMB). The next generation upgraded receiver, known as SPT-3G, is scheduled for deployment in early 2016. SPT-3G will have a focal plane of 2,710 pixels. Each pixel contains six transition-edge sensor (TES) bolometers, sensitive to orthogonal linear polarizations and three frequency bands (90, 150, 220 GHz), for a total of 16,260 detectors in the focal plane. With an order of magnitude more TES bolometers than the current receiver, SPT-3G will open a new regime of sensitivity in high-resolution mapping of the CMB. After four years of observation of 2500 square degrees of the sky, SPT-3G will map the B-mode polarization signature from gravitational lensing of the CMB with high signal-to-noise, a signal that is currently only statistically detected. Lensing B-modes trace the growth of large-scale structure in the universe, which is influenced by neutrino mass. SPT-3G will constrain the sum of neutrino masses with an uncertainty of ~ 0.06 eV, an significant step towards differentiating between hierarchies. Additionally, SPT-3G will detect thousands of new galaxy clusters, extending to lower mass and higher redshifts, through the Sunyaev-Zel'dovich effect. This sample will enable SPT-3G to place improved constraints on the evolution of dark energy, using the cluster abundance to probe the expansion history of the universe. I will discuss these opportunities as well as giving an overview of the SPT-3G detector and readout architecture, including receiver integration status and recent laboratory performance.

Speaker: Amy Bender (Argonne National Laboratory)

dpf_anb_2015.pdf

105 SPIDER: Exploring the dawn of time from above the clouds

Our account of cosmic history begins with inflation, a moment of rapid expansion that set the stage for our universe's evolution. This inflationary epoch should have left a very faint imprint upon the sky at millimeter wavelengths: a “B-mode” (odd-parity) pattern of polarization in the cosmic microwave background (CMB). January 1st saw the successful launch of SPIDER, a powerful balloon-borne instrument designed to hunt these echoes of inflation in the presence of contaminating foregrounds. SPIDER’s 2400 transition-edge sensor bolometers at 95 and 150 GHz and its vantage point 36 km above the Antarctic ice make it the most instantaneously-sensitive CMB polarimeter yet deployed. I will briefly describe SPIDER, its successful 16-day flight, and our first estimates of its performance. I will close with a preview of SPIDER’s second flight, which will employ new receivers designed to peek behind contaminating foregrounds.

Speaker: Jeffrey Filippini (University of Illinois, Urbana-Champaign)

106 Position-dependent power spectrum: a new observable in the large-scale structure

The influence of large-scale density fluctuations on structure formation on small scales is described by the three-point correlation function (bispectrum) in the so-called ''squeezed configurations.'' We show that the ''position-dependent power spectrum'' measures this bispectrum without employing the three-point function estimator. Specifically, we divide a survey into subvolumes, measure the position-dependent power spectrum and the mean overdensity in subvolumes, and find the correlation between these two quantities. This correlation directly measures an integral of the bispectrum dominated by the squeezed configurations. We first measure the integrated bispectrum from cosmological N-body simulations, and show that the measurements agree very well with the theoretical prediction by the ''separate universe approach,'' in which we consider an overdense subvolume as a positively curved universe evolving differently with respect to the background. We then use the same technique to measure the position-dependent correlation function, which measures the integrated three-point function, of BOSS DR10 CMASS sample and PTHalos mock catalogs. We show that the measurements of the mocks agree well with the standard perturbation theory prediction, and the signal sensitive to the galaxy biases and the growth rate. Combining our measurement with the anisotropic clustering and weak lensing of CMASS galaxies, we measure the nonlinear bias of CMASS galaxies.

Speaker: Chi-Ting Chiang (Max-Planck-Institute for Astrophysics)

20150804_DPF_conference.pdf

107 Axion and ALP Dark Matter Search with the International Axion Observatory (IAXO)

The nature of dark matter (DM) remains one of the fundamental questions in cosmology. Axions are one of the current leading candidates for the hypothetical, non-baryonic DM. Especially in the light of LHC slowly closing in on WIMP searches with latest results placing strong restrictions on simplified and constrained models of supersymmetry, axions and axion-like particles (ALPs) provide a viable alternative approach to solving the dark matter problem. The fact that makes them very appealing is that they were initially introduced to solve a long-standing QCD problem in the Standard Model of particle physics. Helioscopes are searching for axions, which could be produced in the core of the Sun via the Primakoff effect. The International Axion Observatory (IAXO) is a next generation axion helioscope aiming at a sensitivity to the axion-photon coupling of 1 - 1.5 orders of magnitude beyond the currently most sensitive axion helioscope (CAST). IAXO will be able to challenge the stringent bounds from SN1987A and test the axion interpretation of anomalous white-dwarf cooling. Beyond standard axions, this new experiment will be able to search for a large variety of ALPs and other novel excitations at the low-energy frontier of elementary particle physics.

Speaker: Julia Katharina Vogel (Lawrence Livermore Nat. Laboratory (US))

DPF2015_IAXO_jvogel.pdf

Neutrino Physics

Conveners: Daniel Hernandez, Irina Mocioiu (Pennsylvania State University), Lindley Winslow (Massachusetts Institute of Technology), Lisa Kaufman (Indiana University)

108 Results from CUORE-0 and a Status Report on CUORE

The CUORE (Cryogenic Underground Observatory for Rare Events) experiment aims to look for neutrinoless double beta decay in 130Te with 750 kg of tellurium oxide bolometers, with a projected sensitivity reaching the inverted mass hierarchy region. CUORE is presently at final stage of construction at Labortori Nazionali del Gran Sasso (LNGS, Italy). In order to demnostrate the performances of the upcoming CUORE experiment CUORE-0, a single CUORE-equivalent tower (52 TeO2 bolometers) built using the same protocols developed for the complete experiment, started taking data at LNGS in spring 2013. In this talk we will present the latest neutrinoless double beta decay results from CUORE-0 and discuss how its background and energy resolution support the CUORE target sensitivity. We will also summarize the status of CUORE and some current R&D activities on bolometers for extending the sensitivity of next-generation double-beta decay experiments.

Speaker: Jonathan Ouellet (U)

DPF2015_Talk_Ouellet.pdf

109 Status Update of the MAJORANA DEMONSTRATOR Neutrinoless Double Beta Decay Experiment

Neutrinoless double beta decay searches play a major role in determining neutrino properties, in particular the Majorana or Dirac nature of the neutrino and the absolute scale of the neutrino mass. The consequences of these searches go beyond neutrino physics, with implications for Grand Unification and leptogenesis. The Majorana Collaboration is assembling a low-background array of high purity Germanium (HPGe) detectors to search for neutrinos double-beta decay in $^{76}$Ge. The MAJORANA DEMONSTRATOR, which is currently being constructed and commissioned at the Sanford Underground Research Facility in Lead, South Dakota, will contain 40 kg (30 kg enriched in $^{76}$Ge) of HPGe detectors. Its primary goal is to demonstrate the scalability and background required for a tonne-scale Ge experiment. This is accomplished via a modular design and projected background of less than 3 cnts/tonne-yr in the region of interest. The experiment is currently taking data with the first of its enriched detectors. Detector characterization, commissioning, and calibration data will be presented from enriched detectors and unenriched detectors operating in a shielded prototype module.

Speaker: Ms Julieta Gruszko (University of Washington)

Gruszko_DPF2015_MJD.pdf

110 Barium Tagging in Solid Xenon for the nEXO Experiment

The proposed nEXO experiment utilizes a tonne-scale liquid xenon time projection chamber to search for neutrinoless double beta decay in xenon-136. A critical concern for any rare decay search is reducing or eliminating backgrounds that cannot be distinguished from signal. A powerful background discrimination technique is positive identification of the daughter atom of the decay, in this case barium. We are developing a scheme to capture the barium daughter in solid xenon with a cryogenic probe and detect the barium by laser-induced fluorescence. This presentation reports results on imaging of small numbers of barium atoms frozen in a solid xenon matrix.

Speaker: Mr Christopher Chambers (Colorado State University)

DPF2015_ChrisChambersFinal.pdf

DPF2015_ChrisChambersFinal.pptx

111 Search for heavy Majorana neutrinos in same-sign dilepton + jets events in pp collisions at √s = 8 TeV

Several extensions of the Standard Model predict heavy Majorana neutrinos. We consider production of these particles at the LHC and utilize the fact that they are their own antiparticle, so processes that violate lepton number conservation by two units are possible. We report on a search for heavy Majorana neutrinos in the same sign lepton plus jets channel. We look for same sign leptons with at least two jets from the decay of an accompanying W boson. The data correspond to an integrated luminosity of 19.7 fb^-1 of proton-proton collisions at a center-of-mass energy of 8 TeV, collected with the CMS detector at the CERN LHC. No excess of events is observed beyond the expected standard model background and upper limits are set on the mixing element of the heavy Majorana neutrino with the standard model neutrinos, as a function of Majorana neutrino mass for masses in the range of 40–500 GeV.

Speaker: Emrah Tiras (University of Iowa (US))

DPF2015_Majorana_Final_ETiras.pdf

EWK and Higgs Sector: Vector Boson Scattering

Convener: Shih-Chieh Hsu (University of Washington, Seattle)

112 Recent Standard Model electroweak measurements at ATLAS

This talk will briefly summarize some of the more recent electroweak measurements at ATLAS of diboson and triboson production. Measurements of these electroweak production rates are of great importance in testing the Standard Model at the energy frontier. A generic search for new physics phenomena is carried out by measuring the triple and quartic gauge boson couplings and comparing with the precise Standard Model prediction.

Speaker: Yusheng Wu (University of Michigan; Institute of Physics, Academia Sinica)

RecentEWKMeasurement-V2.pdf

113 Multiboson measurements and limits on anomalous gauge couplings with the CMS experiment

Recent measurements of multiboson production from the CMS experiment will be presented, as well as limits on anomalous triple and quartic gauge couplings. Precision measurements of multiboson production allow a basic test of the Standard Model, where higher order QCD and electroweak corrections can be probed. In addition searches of physics beyond the Standard Model in multiboson final states rely on precise determination of the Standard Model multiboson processes. The presence of triple and quartic gauge couplings in multiboson production also allows for tests of modification of these vertices from new physics. Prospects for future measurements will also be shown. With the increased center of mass energy of the LHC and the integrated luminosity that will be collected in LHC Run 2, the limits on anomalous gauge couplings will improve significantly.

Speaker: Joshua Milo Kunkle (University of Maryland (US))

dpf_multibosons_v6.pdf

114 Deep Learning and Vector Boson Scattering

The unitarization of the longitudinal Vector Boson Scattering (VBS) cross section by the Higgs boson is a fundamental prediction of the Standard Model which has not been experimentally verified. In the first LHC run, ATLAS and CMS presented the first studies of VBS in events with two leptonically decaying same sign W bosons produced in association with two jets. This channel has the advantage of having very small backgrounds compared to other VBS channels. However, the two neutrinos in the final state make full kinematic event reconstruction and hence evaluation the longitudinal scattering fraction difficult. The angular distributions of the leptons in the W boson rest frame, which are commonly used to fit polarization fractions, are not readily available due to the missing information resulting from the unmeasured neutrinos. In this talk we circumvent this problem by using deep machine learning to recover the angular distributions from measurable event kinematics, and show sensitivities to longitudinal vector boson scattering in future LHC runs. This method can also easily be applied to opposite-sign WW studies, or more generally in any situation where desired quantities are not directly calculable and must be inferred.

Speaker: Jacob Alexander Searcy (University of Michigan (US))

DPF Deep Learning2.pdf

Quark and Lepton Flavor Physics

Conveners: J Michael Williams (Massachusetts Inst. of Technology (US)), Jure Zupan (University of Cincinnati)

115 Lattice inputs for Flavor

Speaker: Daping De

116 New results on semileptonic b decays from LHCb

We report new results based on the full Run-I dataset of LHCb on the following topics: R(D*), asls, DeltaMd, Lambda_b -> Lambda_c mu nu form factors, and |V_ub| using charmless semileptonic Lambda_b decays. A measurement of the b-bbar cross section at sqrt(s) = 13 TeV is reported based on the first data from Run-II of the LHC.

Speaker: Mr Marco Fiore (Universita di Ferrara (IT))

Fiore_DPF.pdf

117 Inclusive electron spectrum from B-meson decays and determination of |V_{ub}|

The inclusive electron spectrum from B-meson decays is measured using a sample of 467 million BBbar pairs recorded with the BABAR detector. Contributions from CKM-favored and CKM-suppressed semileptonic B decays, from secondary decays of charm hadrons and from continuum e+e- -> qqbar annihilations are evaluated using a simultaneous fit to data collected at the Y(4S) resonance and at collision energies below the BBbar production threshold. The partial branching fraction BF(B -> Xu l nu, E_min*) is evaluated using four different models for the CKM-suppressed decays as a function of the minimum electron energy in the B rest frame, and corresponding values of |Vub| are determined.

Speaker: Bob Kowalewski (University of Victoria (CA))

electronspectrum.pdf

BSM Physics

Conveners: Kevin Black (Boston University), Nathaniel Craig (UC Santa Barbara), Rouven Essig

118 Search a dark photon at BABAR

We present a search for a dark photon (A'), a new light gauge boson introduced by dark sector models, using data collected by the BABAR experiment. The dark photon is identified through its decay into a lepton pair in the reaction e+e- -> gamma A', A' -> l+l- (l=e,mu). We observe no statistically significant signal, and we set 90% confidence level upper limits on the mixing strength between the photon and dark photon at the level of 10-3 - 10-4 for dark photon masses in the range 0.02 - 10.2 GeV.

Speaker: David Norvil Brown (University of Louisville (US))

Brown_BaBar_DarkPhotonDPF2015_v2.pdf

119 Search for a new pi0-like particle at BABAR

We report on a search for a new pi0-like particle produced in association with a tau-lepton pair at BABAR. These objects, with similar masses and decay modes to neutral pions, could provide an explanation for the apparent non-asymptotic behavior of the pion-photon transition form factor observed by BABAR. No significant signal is observed, and limits on the production cross sections are found to lie below the values needed to explain the excess observed in the form factor data over the asymptotic limit.

Speaker: Alexandre Beaulieu (University of Victoria)

Beaulieu_DPF2015_NewScalars_RevB.pdf

120 Search for light CP-odd Higgs decay with a charm tag at BABAR

We present a search for a light CP-odd Higgs boson (A0) in Upsilon(1S) -> gamma A0, A0 -> ccbar decays. The Upsilon(1S) mesons are selected via the dipion transition Upsilon(2S) -> pi+pi- Upsilon(1S), and the A0 -> ccbar final state is tagged through the reconstruction of various D(*) mesons. No significant signal is observed, and limits on the product branching fraction B(Upsilon(1S) -> gamma A0)xB(A0 -> ccbar) are set at the level of 7x10-5 - 2x10-3 for A0 masses between 4.0 GeV and 9.25 GeV.

Speaker: Richard Kass (Ohio State University (US))

CPoddHiggs_kass.pdf

121 Search for long-lived particles at BABAR

We present a search for neutral, long-lived particles produced in e+e- collisions or neutral B meson decays with the BABAR experiment. These particles are identified through their displaced decays into various flavor combinations of two oppositely charged tracks. No significant excesses in the two-track mass distributions are observed, and limits on the product of the production cross-section, branching fraction, and reconstruction efficiency are set for each final state.

Speaker: Richard Kass (Ohio State University (US))

LongLived_kass.pdf

122 Status of the Fermilab Muon g-2 experiment

The anomalous magnetic dipole moment of the muon can be both measured and computed to very high precision, making it a powerful probe to test the standard model and search for new physics such as SUSY. The previous measurement by the Brookhaven E821 experiment found a discrepancy from the predicted value with over a 3 standard deviation significance. The new g-2 experiment at Fermilab will improve the precision by a factor of four through a factor of twenty increase in statistics and a reduced systematic uncertainty with an upgraded apparatus. The experiment will also carry out an improved search for a muon electric dipole moment. Construction at Fermilab is well underway.

Speaker: Dr James Mott (Boston University)

g-2 Mott DPF 2015.pdf

123 Current status and prospects of the FNAL muon g-2 storage ring

The muon g-2 experiment will test one of the strongest existing hints for new physics by measuring the anomalous magnetic moment of the muon with a precision of 140 parts per billion. In order to reach this challenging goal the magnetic field permeating the storage volume must be shimmed and measured with great detail. The magnetic field has very recently been excited for the first time in over a decade, and the current and anticipated final state of the precision magnetic field will be discussed.

Speaker: Joseph Grange (Argonne National Laboratory)

dpf_storageRing_grange.pdf

LHC Run-2 Detector Performance

Conveners: Anyes Taffard (University of California Irvine (US)), Petra Merkel (Fermi National Accelerator Lab. (US))

124 The upgraded ATLAS Trigger and DAQ system for the second LHC run

After its first shutdown, LHC will provide pp collisions with increased luminosity and energy. In the ATLAS experiment the Trigger and Data Acquisition (TDAQ) system has been upgraded to deal with the increased event rates. The trigger system consists of a hardware Level-1 (L1) and a software based high-level trigger (HLT) that reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of a few hundred Hz. Due to the increased LHC performance, the ATLAS trigger will have to face roughly five times higher trigger rates. In order to maintain high efficiency to select relevant physics processes, the trigger system is enriched with improvements both in the L1 system, for calorimeter and muon selections and a new topological processor, and with finely optimized HLT algorithms able to identify leptons, hadrons and global event quantities like missing transverse energy. The Data Flow (DF) element of the TDAQ is a distributed hardware and software system responsible for buffering and transporting event data from the Readout system to the HLT and to the event storage. The DF has been reshaped in order to profit from the technological progress and to maximize the flexibility and efficiency of the data selection process. The updated DF is radically different from the previous implementation both in terms of architecture and expected performance. The pre-existing two level software filtering, known as L2 and the Event Filter, and the Event Building are now merged into a single process, performing incremental data collection and analysis. This design has many advantages, among which are: the radical simplification of the architecture, the flexible and automatically balanced distribution of the computing resources, the sharing of code and services on nodes. The network system, that connects the HLT processing nodes to the Readout and the storage systems has also evolved, with higher aggregate throughput and port density and enhanced fault tolerance and redundancy, to provide connectivity as required by the new architecture. We will discuss the design choices, the strategies employed to minimize the data-collection and filtering latency, the results of scaling tests done during the commissioning phase and the operational performance after the first months of data taking.

Speaker: Kevin Black (Boston University)

DPF_Trigger.pdf

125 The Upgrade of the ATLAS Electron and Photon Triggers towards LHC Run 2 and their Performance

Electron and photon triggers covering transverse energies from 5 GeV to several TeV are essential for signal selection in a wide variety of ATLAS physics analyses to study Standard Model processes and to search for new phenomena. Final states including leptons and photons had, for example, an important role in the discovery and measurement of the Higgs particle. Dedicated triggers are also used to collect data for calibration, efficiency and fake rate measurements. The ATLAS trigger system is divided in a hardware-based (Level 1) and a software based high level trigger (HLT), both of which were upgraded during the long shutdown of the LHC in preparation for data taking in 2015. The increasing luminosity and more challenging pile-up conditions as well as the planned higher center-of-mass energy demanded the optimisation of the trigger selections at each level, to control the rates and keep efficiencies high. To improve the performance multivariate analysis techniques are introduced at the HLT. The evolution of the ATLAS electron and photon triggers and their performance will be presented, including initial results from the early days of the LHC Run 2 operation.

Speaker: Gabriella Pasztor (Carleton University (CA))

DPF2015HLTEgamma_final1.pdf

126 Precision electromagnetic calorimetry at the energy frontier: CMS ECAL at LHC Run 2

The CMS electromagnetic calorimeter (ECAL) is a high-resolution, hermetic, and homogeneous calorimeter made of 75,848 scintillating lead tungstate crystals. After the successful quest for the Higgs boson, the CMS ECAL is at the forefront of precision measurements and the search for new physics in data from the LHC, which recently began producing collisions at the unprecedented energy of 13 TeV. The exceptional precision of the CMS ECAL, as well as its timing performance, are invaluable tools for the discovery of new physics at the LHC Run 2. The excellent performance of the ECAL relies on precise calibration maintained over time, despite severe irradiation conditions. A set of inter-calibration procedures using different physics channels is carried out at regular intervals to normalize the differences in crystal light transparency and photodetector response between channels, which can change due to accumulated radiation. In this talk we present new reconstruction algorithms and calibration strategies which aim to maintain, and even improve, the excellent performance of the CMS ECAL under the new challenging conditions of Run 2.

Speaker: Andrea Massironi (Northeastern University (US))

Aug-04_DPF2015_ECAL_Massironi.pdf

127 Jets and missing transverse energy performance in ATLAS with early Run 2 data

The reconstruction of jets and missing transverse energy has proved to be of extreme importance in Run 1 of the LHC, and has great potential to uncover new physics with Run 2 data. ATLAS has implemented and commissioned several new techniques for the analysis and interpretation of hadronic final states at the LHC. These include event-by-event pile-up subtraction algorithms for jets and missing transverse energy, pile-up jet identification techniques and a rich suit of analyses that have allowed reaching uncertainties of the order of 1-3% in the jet and soft missing transverse energy scales and resolutions. The excellent ATLAS detector capabilities, in particular its high resolution longitudinally segmented calorimeter and inner detector, have enabled the development of complex clustering and calibration algorithms for the reconstruction of jets and missing transverse energy and their validation and calibration in data using large datasets collected during 2012. A summary of the most modern jet and missing transverse energy tools and analyses developed in ATLAS, and their calibrations are presented, using extensive Run 1 data and the first studies using Run 2 Monte Carlo simulations and early data.

Speaker: David Miller (University of Chicago (US))

Miller_DPF2015_5Aug2015.pdf

Accelerators, Detectors, Computing

Conveners: Michael Aaron Kagan (SLAC National Accelerator Laboratory (US)), Toyoko Orimoto (Northeastern University (US))

128 Surface-Engineered Photocathode for Tunable Photoemissive Properties

Photocathode emission properties are critical for electron beam applications such as photoinjectors for free electron lasers (FEL) and energy recovery Linacs (ERL). We investigate whether emission properties of photocathodes can be manipulated through the engineering of the surface electronic structure. The multilayers described here have been predicted to have emission properties in correlation with the film thickness. This paper describes how ultra-thin multilayered MgO/Ag/MgO films in the crystallographic orientations (001) and (111) multilayers were synthesized and characterized. We present results of work function, quantum efficiency and angular emission in correlation with film thickness.

Speakers: Daniel Velazquez (Illinois Institute of Technology), Daniel Velazquez

dpf2015-DVelazquez.pdf

dpf2015-DVelazquez.pdf

dpf2015-DVelazquez.pptx

129 Muon cooling progress and prospects for an S-channel muon collider Higgs factory

Muon-based accelerators have the potential to enable facilities at both the Intensity and the Energy Frontiers. Muon storage rings can serve as high precision neutrino sources, and a muon collider is an ideal technology for a TeV or multi-TeV collider. Progress in muon accelerator designs has advanced steadily in recent years. In regard to 6D muon cooling, detailed and realistic designs now exist that provide more than 5 order-of-magnitude emittance reduction. Furthermore, detector performance studies indicate that with suitable pixelation and timing resolution, backgrounds in the collider detectors can be significantly reduced thus enabling high quality physics results. Thanks to these and other advances in design & simulation of muon systems, technology development, and systems demonstrations, muon storage-ring-based neutrino sources and a muon collider appear more feasible than ever before. A muon collider is now arguably among the most compelling approaches to a multi-TeV lepton collider and an S-Channel Higgs Channel.

Speaker: Prof. Mary Anne Cummings (Muons, Inc.)

Cummings_MuonHiggsFactory.pdf

Cummings_MuonHiggsFactory.pptx

130 Compact Low-Voltage, High-Power, Multi-beam Klystron for ILC: Initial Test Results

Abstract: Initial test results of an L-band multi-beam klystron with parameters relevant for ILC are presented. The chief distinction of this tube from MBKs already developed for ILC is its low operating voltage of 60 kV, a virtue that implies considerable technological simplifications in the accelerator complex. To demonstrate the concept underlying the tube’s design, a six-beamlet quadrant (a 54” high one-quarter portion of the full 1.3 GHz tube) was built and recently underwent initial tests, with main goals of demonstrating rated gun perveance, rated gain, and at least one-quarter of the full 10-MW rated power. These tests, with 10-15 microsec RF pulses, confirmed the rated gain, produced output powers of up to 2.86 MW at 60 kV with high efficiency and 56 dB gain, and showed acceptable beam interception. These results suggest that a full version of the tube should be able to produce up to 11.5 MW. Our initial three-day conditioning campaign without RF drive (140 microsec pulses @60 Hz) was stopped at 53% of full rated duty because of time-limits at the test-site; no signs appeared that would seem to prevent achieving full duty operation (i.e., 1.6 msec pulses @10 Hz). Follow-on tests are planned for later in 2015. __________ *This work was supported by several SBIR grants to Omega-P, Inc. from Department of Energy, Office of High Energy Physics.

Speaker: Sergey Shchelkunov (yale univ., and omega-p, inc)

131 Beam Extinction and Monitoring at the Upcoming Mu2e Experiment

Muon to electon conversion represents a well-known process in physics in which a muon transmutes into an electron and two neutrinos. However, if a neutrinoless conversion were observed, this would represent unambiguous evidence for new physics. The Mu2e experiment at Fermilab will search for neutrionless muon to electron conversion at a sensitivity 10000 better than previously achieved. To accomplish the experiment’s desired sensitivity, late arriving beam-induced backgrounds must be suppressed by a factor of 10^{-10}. This suppression factor, or extinction, will be achieved by a variety of accelerator and beamline techniques. Furthermore, verification and monitoring of the extinction rate will be crucial for the experiment’s success. This talk will discuss the current status and many technical aspects of the Mu2e experiment and will focus on Mu2e’s extinction strategy and monitoring.

Speaker: Prof. Ryan Hooper (Lewis University)

DPF-2015-Mu2e-Extinction-vfinal.pptx

132 New Beam Profile Monitoring System for the Proton Irradiation Facility at the CERN PS East Area

A new beam profile monitoring system (BPM) was developed for the Proton Synchrotron East Area Irradiation Facility at CERN. This new BPM provides 50 channels of low noise acquisition for connection to a pixelated detector consisting of thin foil copper pads positioned on a flex circuit. Five separate data acquisition systems were assembled and delivered to CERN. The systems are fully operational and have been used for sample alignment during proton irradiations in 2014 and 2015. We will present the design of the BPM system and results on its performance during these irradiation periods.

Speaker: Joseph Warner (The Ohio State University)

Joseph Warner DPF 2015.pdf

QCD and Heavy Ions

Convener: Joey Huston (Michigan State University (US))

QCDTevDPF2015.pdf

133 Recent QCD Results from the Tevatron

Recent QCD results from the CDF and D-Zero experiments.

Speaker: Konstantinos Vellidis (Fermilab)

QCDTevDPF2015.pdf

134 Parton shower overview

This is an overview of recent parton shower developments.

Speaker: Stefan Prestel (SLAC)

prestel_talk20150805.pdf

135 Flavor Tagging TeV Jets for BSM and QCD

We present a new scheme for tagging *b*-jets with $p_{T}>500$ GeV, which we call $\mu_{x}$ tagging. At the LHC, the primary method to tag *b*-jets (jets which originate from bottom quarks) relies on tracking their charged constituents. However, when jets are highly boosted, their dense, collimated environment makes precise tracking difficult. Thus, as jet $p_{T}$ approaches 1 TeV, track-based *b*-tags lose efficiency, and the probability to mis-tag light jets rises dramatically. This is a problem, since many heavy BSM resonances ($W^{\prime}\rightarrow tb$, $Z^{\prime}/G^{*}\rightarrow t\bar{t}/b\bar{b}$, etc.) require tagging at least one energetic *b*-jet and rejecting the light-jet background. Using muons from semi-leptonic *b*-hadron decay, we define a variable $x$ which encodes angular correlations between the muon and the boosted subjet of the decay. Requiring $x\leq x_{max}$ allows us to tag *b*-jets and effectively discriminate the light-jets (including those which undergo gluon splitting). This is especially useful at ATLAS, which has excellent capabilities for standalone muons. We find an efficiency to tag *b*-jets, *c*-jets and light-jets of $\epsilon_{b}\approx14\%$, $\epsilon_{c}\approx6.5\%$ and $\epsilon_{light}\approx0.65\%$ respectively (where primary gluons splitting to heavy flavors are classified as light-jets). For heavy flavor jets (*b* / *c*), these efficiencies are essentially flat (over $-2.5\leq\eta\leq2.5$ and $0.5\,\mathrm{TeV}\leq p_{T}\leq2.1\,\mathrm{TeV}$). For light-jets, the rejection rate improves slightly with $p_{T}$. This scheme could be immediately useful in discovering a heavy, "leptophobic" $Z^{\prime}$ in the dijet channel. We simulate such a $Z^{\prime}$ at several TeV-scale masses and, using only the $\mu_{x}$ tag, predict a substantial increase in the sensitivity to discover heavy $Z^{\prime}$ at the LHC Run II. Additionally, since $\mu_{x}$ and track-based tagging are not mutually exclusive, using both should maximize the total *b*-tagging efficiency.

Speaker: Keith Pedersen (Illinois Institute of Technology)

APS-DPF-2015_K_Pedersen.pdf

Top Physics

Conveners: Andrew Ivanov (Kansas State University (US)), Christopher Neu (University of Virginia (US))

136 Lorentz and CPT Violation in Top-Quark Production

Signals for Lorentz and CPT violation can appear in a wide range of experiments including hadron colliders like the LHC. We present a calculation of the Lorentz-violating cross section for top-quark pair production via gluon fusion. This process dominates at the LHC, and analysis of LHC data should permit sharpening the constraints on top-quark Lorentz violation obtained recently by the D0 Collaboration. We also present a separate calculation of single-top production, which is sensitive to CPT violation. Data from the LHC can be used to measure coefficients for CPT violation in the top-quark sector for the first time.

Speaker: Zhi Liu (Indiana University)

Zhi_Liu.pdf

137 Forward-backward asymmetry in top pair production at CDF

The forward-backward asymmetry of the top quark pair production at the Tevatron experiments is one of the hottest topics in particle physics in the recent years. It provides unique precision tests of the standard model and of physics beyond the standard model. We present the latest measurement of the top forward-backward asymmetry in the dilepton final state and summarize the legacy results of the top quark forward-backward asymmetry at CDF.

Speaker: Ziqing Hong

ZH_08052015.pdf

138 Measurement of the charge asymmetry in top quark pair production in 8 TeV $pp$ collision data collected by the ATLAS experiment

A summary of results for the top quark charge asymmetry, $\text{A}_{\text{C}}$, measured using 20.3 fb$^{-1}$ of data recorded with the ATLAS detector at a center-of-mass energy $\sqrt{s}=8$ TeV is presented. Events where either both top quarks decay leptonically (dileptonic), or one top quark decays leptonically and the other hadronically (semi-leptonic) are considered. The semi-leptonic channel is split into a boosted analysis, where the top decay products overlap in the detector, and a resolved analysis, where the top decay products are well-separated in the detector. All analyses fully reconstruct the $t\bar{t}$ system and apply an unfolding procedure to estimate $\text{A}_{\text{C}}$ at the parton level. All measurements are consistent with Standard Model predictions.

Speaker: Daniel Marley (University of Michigan (US))

DPF2015_TopAC_Marley.pdf

15:30 Cafe Break

AstroParticle, Cosmology, Dark Matter Searches, and CMB

Convener: Tomasz Biesiadzinski

139 Search for new phenomena in final states with an energetic photon or jet and large missing transverse momentum in pp collisions with the ATLAS detector

Searches for new phenomena in final states with an energetic photon or jet and large missing transverse momentum (MET) are presented. The searches use 20 $\text{fb}^{-1}$ of $\sqrt{s}$ = 8 TeV data collected with the ATLAS detector at the LHC. Good agreement is observed between the number of events in data and Standard Model expectations. The results are interpreted as exclusion limits on the pair production of weakly interacting dark matter candidates, on models with large extra spatial dimensions, and on the production of very light gravitinos in a gauge-mediated supersymmetric model. Also presented are prospects for dark matter searches at $\sqrt{s}$ = 14 TeV, together with an overview of the models in which Run 2 searches in the photon + MET and jet + MET channels will be interpreted.

Speaker: Fuquan Wang (University of Wisconsin-Madison Department of Physics)

fwang20150805.pdf

140 Probing Theories of Dark Matter with Direct Detection

In the event of dark matter direct detection, learning in a data-driven way about the interactions between dark matter and the Standard Model will be of utmost importance. In new work, coworkers and myself have demonstrated the possibilities for Bayesian model selection of a wide class of theories in a potential future situation where direct detection is confirmed by a variety of different targets. We find that multiple detector elements are needed to confidently extract the details of the dark mater - Standard Model interaction. After properly accounting for the UV particle physics and the low-energy nuclear physics, we also find that currently proposed detectors (crucially including a target with iodine or fluorine) are capable of breaking degeneracies between a very large range of interesting models.

Speaker: Samuel McDermott

mcdermott-dmdd-aps.pdf

141 DAMIC results : Low mass WIMP(~<5GeV) direct detection with scientific CCDs

A large body of astronomical evidence across all length scales, from galaxy rotation curves, to lensing studies and spectacular observations of galaxy cluster collisions, to cosmic microwave background measurements, all points to the existence CDM(Cold Dark Matter) particles. WIMP(Weakly Interacting Massive Particles) represent a class of dark matter particles that froze out of thermal equilibrium in the early universe with a relic density that matches observation, meanwhile, it could "naturally" solve the gauge hierarchy problem. This is the so called WIMP miracle. Many theoretical models beyond the Standard Model provide natural candidates for WIMPs, but the range of WIMP mass is huge : from 1GeV to 100TeV. DAMIC dedicates to hunt low mass(~< 5GeV) WIMP thanks to its extremely low noise, 2e^-(RMS). In this presentation, I will make a brief review on our work at first, but my main emphasis would be such two aspects : (1), quenching factor measurement for silicon with (sub)keV recoil energy using mono-energy(2MeV) neutron source. Currently, the measured lowest recoil energy for silicon is ~4 keV. (2), the limit of cross-section vs WIMP mass using different EFT operators and a few WIMP velocity model(s). Right now, DAMIC reached the lowest mass limit by a typical SI(Spin Independent) analysis, it's meaningful to show if EFT model has been applied. DAMIC is an international collaboration. DAMIC detector has taking data since 2013 in Snolab, Canada.

Speaker: Junhui Liao

DPF2015-JunhuiLIAO-New.pdf

142 World-leading Dark Matter Limits with PICO-2L and PICO-60

The PICO Collaboration, formed from the merger of the Chicago-based COUPP and the Canadian-based PICASSO experiments, uses bubble chambers to search for dark matter. Bubble chambers are a unique dark matter detector technology. They provide very high $~10^{10}$ intrinsic electron recoil rejection, the ability to switch nuclear targets, acoustic rejection of alpha events, simple data acquisition, and low construction costs. The PICO-2L bubble chamber exposed a heavily fluorinated C$_3$F$_8$ target fluid for 211.5 kg-days in the 2100 meter deep SNOLAB underground laboratory. In-situ measurements and measurements at the University of Montreal confirm the detector is sensitive to nuclear recoils with energies as low as 4 keV while maintaining excellent electron recoil and alpha rejection capabilities. A background of nuclear recoil event candidates were observed during the run. The candidate events exhibit timing characteristics that are not consistent with the hypothesis of a uniform time distribution, and no evidence for a dark matter signal is claimed. Despite the background, these data provide the most sensitive direct detection constraints on WIMP-proton spin-dependent scattering to date. World-leading results are also reported for the PICO-60 bubble chamber, a scale-up of the COUPP4 bubble chamber operated with $CF_3I$ target fluid at the SNOLAB underground laboratory.

Speaker: Orin Harris (Indiana University South Bend)

Orin_PICO_DPF.pdf

143 Results of DM-Ice17 and Prospects of the DM-Ice Experiment

The DM-Ice experiment aims at the direct detection of annually-modulating WIMP (Weakly Interacting Massive Particle) dark matter signal using NaI(Tl) detectors. DM- Ice17, the first-generation detector with 17 kg of NaI(Tl), was deployed in the South Pole ice in December 2010 and has been successfully operated since then. R&D efforts for the quarter-tonne scale detector are well underway at the Yale Wright Laboratory and the Boulby Underground Laboratory in UK. I will present the experiment and the results of DM-Ice17 with more than three years of data. I will also discuss the science potential of the full-scale DM-Ice detector.

Speaker: Kyungeun Lim (Yale University)

Assembly2.mov

IceCube.mp4

lim-dpf2015-dmice.pdf

144 Status of the KIMS-NaI experiment

A number of experiments are operating around the world that search for WIMP, one of the Dark Matter candidates. Among these experiments, DAMA is unique in that it has consistently claimed the observation an annual WIMP modulation signal while others rule out the DAMA signal region in the parameter space. The KIMS-NaI experiment aims to confirm the DAMA observation unambiguously using same type of crystal detectors (NaI(Tl)). We have developed low-background NaI(Tl) crystals and carried out tests in the Yangyang underground laboratory. The result of our NaI detectors and future prospects of the experiment will be presented.

Speaker: Ms Kyungwon Kim (Center for Underground Physics, Seoul National University)

Status of the KIMS-NaI experiment_DPF.pdf

145 XENON: New Results and Prospects

The XENON dark matter project aims at finding direct evidence for the scattering of weakly interacting massive dark matter particles (WIMPs) with nuclei in an ultra-low background liquid xenon detector. The XENON100 detector, located at LNGS in Italy, collected dark matter data between 2008 and 2014, producing some of the best limits in the field. In this talk, we present new results from the last science run of the detector, including tests on previously claimed observations of annual modulation. The next generation detector, XENON1T, is presently being commissioned at LNGS and the first data taking of the experiment is expected to start by the end 2015. We will summarize the current status and physics reach of the experiment.

Speaker: Dr Patrick de Perio (Columbia University)

150805-deperio_xenon_dpf_michigan_v5.pdf

Neutrino Physics

146 KPipe: A Short-Baseline Muon-Neutrino Disappearance Experiment using Neutrinos from Kaon Decay-at-rest

Recently, anomalies consistent with neutrino oscillations with mass splittings on the order of 1 eV2 have been observed. These anomalies have been seen in experiments measuring nue appearance and nue/nue-bar disappearance, while no corresponding evidence for muon neutrino disappearance has been detected. A common interpretation of the anomalies involves postulating the existence of one or more “sterile” neutrinos that, unlike the three Standard Model neutrinos, do not interact via the electroweak force. While models with sterile neutrinos can explain the current data, they all require that some amount of muon neutrino disappearance must occur, with several models indicating that evidence for the process might have been just below the sensitivities of past experiments. In this talk, I present a new type of experiment that will search for muon neutrino disappearance at the Materials and Life Science Facility (MLF), which is a part of the JPARC accelerator complex in Tokai, Japan. The facility features a high intensity, pulsed beam of 3 GeV protons used to produce neutron, muons, and neutrinos for various experiments. In our proposal, we would measure mono-energetic neutrinos coming from kaon decay-at-rest with a detector consisting of a 3 m diameter by 90 m long pipe filled with liquid scintillator. This setup would aim to measure directly the L/E oscillation wave in the event rate along the length of the detector. Such a signal would provide convincing evidence for a sterile neutrino and avoids some of the difficulties in past experiments in characterizing the incoming neutrino flux and modeling neutrino-nucleus interaction cross sections.

Speaker: Spencer Axani (MIT)

DPF talk 08:05:2015.pdf

147 Looking for Sterile Neutrinos with NOvA

Contradictory evidence has been presented on the issue of neutrino mixing between the three known active neutrinos and light sterile neutrino species. Short-baseline neutrino oscillations observed by the LSND and MiniBooNE experiments, the collective evidence of the reactor neutrino anomaly, and the gallium anomaly all point towards sterile neutrinos with mass at the 1 eV level. While these results are tantalizing, they are not conclusive as they are in tension with null results from other short-baseline experiments, and with disappearance searches in long-baseline and atmospheric experiments. Resolving the issue of the existence of light sterile neutrinos has profound implications for both particle physics and cosmology. The NOvA (NuMI Off-Axis νe Appearance) experiment may clarify the situation by searching for disappearance of active neutrinos from the NuMI (Neutrinos from the Main Injector) beam over a baseline of 810 km. In this talk, we will introduce how NOvA can look for sterile neutrino mixing, with focus on disappearance of neutral current (NC) neutrino events. We will present NOvA’s sensitivity to a sterile oscillation signal and, for the case where no evidence is found, the NOvA prospects for improving existing constraints on sterile neutrino admixture in scenarios including one sterile neutrino.

Speaker: Shaokai Yang (University of Cincinnati)

LookingforsterileneutrinowithNOvA.1.1.pdf

148 Sensitivity and Discovery Potential of the PROSPECT Experiment

Measurements of the reactor antineutrino flux and spectrum compared to model predictions have revealed an apparent deficit in the interaction rates of reactor antineutrinos and an unexpected spectral deviation. PROSPECT, the Precision Reactor Oscillation SPECTrum measurement, is designed to make a precision measurement of the antineutrino spectrum from a research reactor and search for signs of sterile neutrinos. PROSPECT will be located at the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory and make use of a Highly Enriched Uranium reactor for a measurement of the pure U-235 antineutrino spectrum. An absolute measurement of this spectrum will constrain reactor models and improve our understanding of the reactor antineutrino spectrum. Additionally, the planned 2-ton Lithium-doped liquid scintillator detector is ideally suited to perform a search for sterile neutrinos on the eV scale. This talk will focus on the sensitivity and discovery potential of PROSPECT and the detector design to achieve these goals.

Speaker: Dr Karin Gilje (Illinois Institute of Technology)

DPF_PROSPECT_KEG_final.pdf

149 Development of PROSPECT detectors for precision antineutrino studies

PROSPECT, the Precision Oscillation and Spectrum Experiment, will use two segmented detectors positioned 7-20m from the High Flux Isotope Reactor (HFIR) to measure the antineutrino spectrum of uranium-235 and perform a search for eV-scale sterile neutrinos. PROSPECT has developed Li-loaded liquid scintillator detectors for efficient identification of reactor antineutrinos and performed background studies near the HFIR. Multiple detectors have been built and characterized to understand the optical performance of the scintillator and pulse shape discrimination capabilities for enhanced background rejection. The results from this R&D effort will be discussed, in the context of the design and physics potential of PROSPECT.

Speaker: Ms Danielle Norcini (Yale University)

DPF15_PROSPECTdetectors_v6.pdf

150 Fast Neutron Detection with MITPC

Fast neutrons are an important background in a variety of particle physics experiments, but data on neutron flux as a function of depth underground is sparse. MITPC is a directional fast neutron detector that measures neutron flux as a function of energy and direction, and is designed for easy deployment to various sites. MITPC has completed runs at the near and far halls of the reactor-based neutrino experiment Double Chooz. Now, MITPC is running on the Booster Neutrino Beamline at Fermilab, where its measurements will serve the Short-Baseline Neutrino program. This talk will present the latest MITPC results.

Speaker: Marjon Moulai (MIT)

DPF2015_talk.pdf

151 Cosmogenic isotope production by stopping muons in Double Chooz

Using the Double Chooz reactor neutrino detector, we have measured the products of $\mu^-$ capture on ${}^{12}$C, ${}^{13}$C, ${}^{14}$N and ${}^{16}$O. Over a period of 490 days, we collected $2.3\times10^6$ stopping cosmic $\mu^-$, of which $1.8\times10^5$ captured on these nuclei in the inner detector scintillator or acrylic vessels. The resulting isotopes were tagged using prompt neutron emission (when applicable), the subsequent beta decays, and, in some cases, $\beta$-delayed neutrons. Production of these $\beta$n isotopes, primarily ${}^9$Li, which are $\bar\nu_\mathrm{e}$ backgrounds, was found at a significance of 5.0$\sigma$. The probability of ${}^9$Li per capture on ${}^{\mathrm{nat}}$C is $(2.4\pm0.9\mathrm{(stat)}\pm0.1\mathrm{(syst)})\times10^{-4}$.

Speaker: Matthew Strait (University of Chicago)

dpf_stoppingmuon_talk.pdf

EWK and Higgs Sector: Higgs Properties - Mass and Lifetime

Convener: Ian Lewis (SLAC)

152 Combined Measurement of the Higgs Boson Mass in pp Collisions at s√=7 and 8 TeV with the ATLAS and CMS Experiments

The mass of the Higgs boson is an important free parameter of the Standard Model (SM). Given the mass, all properties of the SM Higgs boson can be predicted. In this talk, I summarize the measurement of the Higgs boson mass based on the combined Run 1 datasets from the ATLAS and CMS experiments collected at √s = 7 TeV and 8 TeV at the LHC, using the high-resolution diphoton and four-lepton decay channels.

Speaker: Hongtao Yang (University of Wisconsin (US))

lhc_mass_combination_hongtao.pdf

153 Lifetime and quantum numbers of the Higgs boson using the decay $H\to4\ell$

Constraints on the lifetime and quantum numbers of the recently discovered Higgs boson are obtained from $H\to4\ell$ events using the full dataset recorded by the CMS experiment during the LHC Run1. The measurement of the Higgs boson lifetime is derived from limits set on its flight distance within the CMS detector and a limit of the total width obtained from an off-shell production technique. The width from off-shell production is also generalized to include additional anomalous couplings of the Higgs boson to two electroweak bosons. Using the events on the resonance peak, a wide range of spin-two and any mixed-parity spin-one models are excluded at a 99% confidence level or higher. Under the hypothesis that the resonance is a spin-zero boson, the tensor structure of the interactions of the Higgs boson with two vector bosons $ZZ$, $Z\gamma$, and $\gamma\gamma$ are investigated and limits on nine anomalous contributions are set. All observations are consistent with the expectations for the 125 GeV standard model Higgs boson with quantum numbers $J^{PC}=0^{++}$ and a width of about 4 MeV.

Speaker: Christopher Blake Martin (Johns Hopkins University (US))

ChrisMartin_presentation.pdf

154 The lifetime of the electroweak vacuum

If the Standard Model (SM) is valid up to extremely high energy scales, then the Higgs potential becomes unstable at approximately 10^11 GeV. Calculations of the lifetime showed that it vastly exceeds the age of the Universe. However, these calculations are extremely sensitive to effects from Planck scale higher-dimensional operators and, without knowledge of these operators, firm conclusions about the lifetime of the SM vacuum cannot be drawn. It is surprising that the Planck scale operators can have such a large effect when the instability is at 10^11 GeV. There are two reasons for the size of this effect. In typical tunneling calculations, the value of the field at the center of the critical bubble is much larger than the point of the instability; in the SM case, this turns out to be numerically within an order of magnitude of the Planck scale. In addition, tunneling is an inherently non-perturbative phenomenon, and may not be as strongly suppressed by inverse powers of the Planck scale. We include effective higher dimensional Planck-scale operators and show that they can have an enormous effect on the tunneling rate.

Speaker: Marc Sher (William and Mary College)

vacuumdpf.pptx

Quark and Lepton Flavor Physics

155 First measurement of the differential branching fraction and CP asymmetry of the B+ → π+μ+μ− decay

Speaker: Tobias Tekampe (Technische Universitaet Dortmund (DE))

Bu2pimmDPF.pdf

156 Measurement of CP violation in D+ -> pi+pi0 decays at BABAR

157 Amplitude analysis of charmless B decays at LHCb

Speaker: Paula Alvarez Cartelle (Imperial College Sci., Tech. & Med. (GB))

Charmless_amplitude_LHCb.pdf

158 Recent results on charmless hadronic B decays at Belle

Speaker: Bilas Pal (University of Cincinnati)

DPF2015_Bilas_Pal_1.pdf

159 Study of B± → π±π∓π± at Belle

Speaker: Yao Li (Virginia Tech)

20150805 DPF B3pi.pdf

BSM Physics

160 Test of Lorentz Invariance from Compton Scattering

In the recent times, test of Lorentz Invariance has been used as a means to probe theories of physics Beyond the Standard Model, especially those such as extensions to String Theory and Quantum Gravity. The announcement of the discovery of primordial gravitational waves by the BICEP2 collaboration, points to a possibility of gravity being quantized. Therefore tests of Lorentz invariance could go a long way in setting the stage for possible quantum gravity theories which are beyond the standard model. We describe a simple way of utilizing electron polarimeters, which are a critical beam instrument at precision and intensity frontier nuclear physics labs such as Stanford Linear Accelerator Center (SLAC) and Jefferson Lab (JLab), to limit the dependence of speed of light with the energy of the photons. We also describe a way of limiting directional dependence of speed of light at previously unprecedented levels of precision by studying the sidereal variations. The method and preliminary results from this study as well as possible limits on CPT violating Standard Model Extension parameters will be presented.

Speaker: Mr Prajwal Mohanmurthy (MIT)

Talk.pptx

161 Radiative B decays as probes of physics beyond the Standard Model (BSM)

The LHCb experiment has performed during Run-I of the LHC several studies sensitive to physics that may affect, among other observables, the polarisation of the emitted photon and the branching fractions of several decay modes. In this talk, the latest results on radiative decays are presented, which access different sources of physics BSM: on one side, the branching fraction of the $B_s^0\to J/\psi\gamma$ decay is sensitive to the presence of a charged Higgs, and, on the other, the $B_s^0\to\phi\gamma$ time-dependent CP asymmetry gives access to the polarisation of the photon, which can be affected by the existence of right-handed currents or the MSSM.

Speaker: Zhirui Xu (Ecole Polytechnique Federale de Lausanne (CH))

DPF2015-Zhirui-talk.pdf

LHC Run-2 Detector Performance

162 The updated ATLAS Jet Trigger for the LHC Run II

After the current shutdown, the LHC is about to resume operation for a new data-taking period, when it will operate with increased luminosity, event rate and centre of mass energy. The new conditions will impose more demanding constraints on the ATLAS online trigger reconstruction and selection system. To cope with such increased constraints, the ATLAS High Level Trigger, placed after a first hardware-based Level-1 trigger, has been redesigned by merging two previously separated software-based processing levels. In the new joint processing level, the algorithms run in the same computing nodes, thus sharing resources, minimizing the data transfer from the detector buffers and increasing the algorithm flexibility. The Jet trigger software selects events containing high transverse momentum hadronic jets. It needs optimal jet energy resolution to help rejecting an overwhelming background while retaining good efficiency for interesting jets. In particular, this requires the CPU-intensive reconstruction of tridimensional energy deposits in the ATLAS calorimeter to be used as the basic input to the jet finding algorithms. To allow this costly reconstruction step, a partial detector readout scheme was developed, that effectively suppresses the low activity regions of the calorimeter and significantly reduces the needed resources. In this paper we describe the overall jet trigger software and its physics performance. We then focus on detailed studies of the algorithm timing and the performance impact of the full and partial calorimeter readout schemes. We conclude with an outlook of the jet trigger plans for the next LHC data-taking period.

Speaker: Sebastien Prince (McGill University (CA))

DPF-JetTrigger.pdf

163 Real-time Flavour Tagging Selection in ATLAS: ready for LHC Run-2

In high-energy physics experiments, online selection is crucial to select interesting collisions from the large data volume. ATLAS b-jet and tau triggers are designed to identify heavy-flavour content in real-time and provide the only option to efficiently record events with fully hadronic final states containing b-jets or hadronic tau decays. In doing so, two different, but related, challenges are faced. The physics goal is to optimise as far as possible the rejection of light jets, while retaining a high efficiency on selecting b-jets or hadronic taus and maintaining affordable trigger rates without raising jet energy thresholds. This maps into a challenging computing task, as tracks and their corresponding vertices must be reconstructed and analysed for each jet above the desired threshold, regardless of the increasingly harsh pile-up conditions. We present an overview of the ATLAS strategy for online b-jet and tau selection for the LHC Run 2, including the use of novel methods and sophisticated algorithms designed to face the above mentioned challenges. A first look at the performance in Run 2 data is shown and compared to the performance during Run 1. The ATLAS FastTracKer (FTK) system does global track reconstruction for each event accepted at Level 1 to enable early access to tracking information for the High Level Trigger. We also present the status of the FTK commissioning (expected to be completed in 2016) and discuss how the system can be exploited to improve the current b-jet/tau trigger performance.

Speaker: John Alison (University of Chicago (US))

BJetTrigger.pdf

164 Performance of the CMS endcap muon detector in Run 2

Since the end of LHC Run 1 in 2012, the readout electronics of the innermost ring of the CMS Cathode Strip Chambers (CSC) endcap muon detector have been upgraded to accommodate the larger luminosity and collision energy anticipated in Run 2. A major effort was required to design, install, and commission these new electronics. This talk will summarize the improvements made during this upgrade and present the performance of the CSC detector during the early stages of Run 2.

Speaker: Wells Wulsin (Ohio State University (US))

20150805_DPFCSCPerformance.pdf

165 Muon reconstruction and identification performance in ATLAS at Run-II

The ATLAS muon reconstruction has been improved for the Run-II of the LHC.​ In this presentation, we will discuss the new reconstruction algorithm and its performance as measured during the early run of the LHC in 2015 at sqrt(s)= 13 TeV using samples of J/ψ→μμ and Z→μμ decays. Reconstruction and identification efficiency, transverse momentum resolution and momentum scales are measured in the various regions of the detector and for muon momenta between 5 and hundreds of GeV.

Speaker: Dongliang Zhang (University of Michigan (US))

Atlas_Muon_performance_DongliangZhang.pdf

Accelerators, Detectors, Computing

166 Low Voltage Power for the ATLAS New Small Wheel

The New Small Wheel (NSW) is an upgrade for enhanced triggering and reconstruction of muons in the forward region of the ATLAS detector. It will have over 2.5 million readout channels and over 7400 Front End boards. The large LV power demands - 51kW at 1.2V to 2.5V - necessitate a point-of-load architecture with on-detector power conversion to meet these requirements. We present final results from an extensive campaign to test commercial power devices in radiation and magnetic fields. An alternate solution is described, based on a custom, radiation-hard power conversion ASIC produced by CERN. We detail the challenges and solutions in integrating this device into the NSW mechanical environment, and outline the full resulting power system.

Speaker: Ryan Christopher Edgar (University of Michigan (US))

talk.pdf

167 Micro-pattern detectors based on plasma panels: Past, present, and future developments

Micro-patterned plasma panels are emerging as a new promising particle detector type whose concept originated from plasma-TV technologies. The idea is to utilize the high spatial resolution of hermetically sealed gas cells and transform them into independent micro-Geiger counters, thus creating a scalable, low mass, long life, fast, gas sealed and inexpensive particle tracker. Experimental results will be presented for two distinct 1st generation prototype designs which have yielded volt size pulses (without amplification), signal rise times and time dispersion (for beta particle radiation) of ~ 3 ns, FWHM < 3 ns. Voltage stability and operating window, rate response, and gas mixture results will also be presented. Possible applications in high energy and nuclear physics and goals for future prototypes will be discussed.

Speaker: Merlin Davies (Tel Aviv University (IL))

DPF_PlasmaPanel_Davies.pdf

168 A Straw Tube Tracker for the Mu2e Experiment

The Mu2e experiment will search for neutrinoless conversion of muons into electrons in the field of an aluminum nucleus. The signature of this process is an electron with energy nearly equal to the muon mass. Precise and robust measurement of the outgoing electron momentum is a crucial element of the experiment. We describe the design of a low mass tracking system to meet this requirement. The tracker must operate in a vacuum and a 1 Tesla magnetic field. We have chosen to use about 20,000 thin wall Mylar straws held under tension to avoid the need for supports within the active volume. In addition to measuring distance from the wire by drift time, subnanosecond measurement of signal propagation time will be used to measure position along the wire. Charge will be measured using ADCs to provide particle identification capability. To minimize the number of vacuum penetrations, digitization will be performed on the detector. Readout will use a triggerless, streaming architecture with data transmitted on optical fiber.

Speaker: Jim Popp (York College)

DPF2015-TrackerOverview_V06.pdf

169 Straw Leak Testing for the Mu2e Tracker

The Mu2e experiment at Fermilab will search for the neutrinoless conversion of a muon into an electron in the field of an Al nucleus, with a sensitivity improvement of four orders of magnitude over previous measurements. Observation of this process would be unambiguous evidence for physics beyond the standard model. The signature of muon to electron conversion is a monoenergetic electron with energy nearly equal to the muon mass. Precise tracking with minimal energy loss or multiple scattering is paramount to this measurement. The Mu2e tracker will consist of more than 20,000 thin-walled straw tubes operating in a vacuum of 10-4 torr. It is therefore essential that all straws be leak-tested before installation in the tracker. We will discuss the Mu2e tracker, as well as techniques and equipment developed for quickly and accurately measuring gas leak rates from individual straws.

Speaker: Daniel Ambrose (University of Minnesota)

Mu2e_leak_test_DPF2015.pdf

170 Status of Belle II and SuperKEKB

The Belle II experiment at the SuperKEKB asymmetric energy e+e- collider in Tsukuba, Japan, will start physics data taking in 2018 and will accumulate 50/ab of e+ e- collision data, about 50 times larger than the data set of the earlier Belle experiment. We describe the status and plans for the construction of the Belle II detector and the SuperKEKB accelerator. SuperKEKB background commissioning begins in January 2016. Outer detector construction is expected to complete in 2016. First runs with the Belle II outer detector are expected in 2017.

Speaker: Prof. Carl Rosenfeld

DPF2015_s7c221_150805.pdf

171 The iTOP particle identification detector at Belle II

We describe the iTOP (imaging Time Of Propagation) detector in the Belle detector at the SuperKEKB accelerator, located at KEK in Tsukuba, Japan. The principle of operation, readout and the expected kaon/pion separation capabilities will be described. Status of the detector construction and integration will be discussed.

Speakers: Kurtis Nishimura (University of Hawai), Kurtis Nishimura, Kurtis Nishimura

DPF2015.Nishimura.iTOP.pdf

172 The upgraded KLM detector at Belle II

We describe the KLM (KLong-Muon) detector for the Belle II detector at the SuperKEKB accelerator located at KEK in Tsukuba, Japan. The endcap RPC (Resistive Plate Chamber) detectors used for Belle have been entirely replaced with a scintillator-based system readout out with Si PMTs. The inner two layers of the barrel also been replaced. The readout using "oscilloscope on a chip" based readout electronics will be discussed as well as expected physics performance.

Speaker: Leo Piilonen (Virginia Tech)

KLM-Piilonen.pdf

173 The SiD Detector for the International Linear Collider

The SiD Detector is one of two validated detector designs for the future International Linear Collider. SiD features a compact, cost-constrained design for precision Higgs and other measurements, and sensitivity to a wide range of possible new phenomena. A robust silicon vertex and tracking system, combined with a 5 Tesla central solenoidal field, provides excellent momentum resolution. The highly granular calorimeter system is optimized for Particle Flow application to achieve very good jet energy resolution over a wide range of energies. Details of the proposed implementation of the SiD subsystems, as driven by the physics requirements, will be given. Integration with the accelerator, the push-pull mechanism, and the detector assembly procedures at the Kitakami site will be described, together with the estimated timeline for construction in relation to the overall ILC Project.

Speaker: Andrew White (University of Texas at Arlington (US))

SiD_Detector_for_ILC_DPF2015.pdf

SiD_Detector_for_ILC_DPF2015.pptx

QCD and Heavy Ions

Convener: Joey Huston (Michigan State University (US))

QCDTevDPF2015.pdf

174 Making Sense of the XYZ Mesons from QCD

The XYZ mesons are unexpected mesons discovered in the last decade that contain a heavy quark and antiquark but have properties that suggest they also have additional constituents. Many of them are surprisingly narrow, and several are definitely tetraquark mesons. Their existence presents a serious challenge to our understanding of the spectrum of QCD. I will explain how the Born-Oppenheimer approximation may provide a framework for understanding the XYZ mesons within QCD.

Speaker: Eric Braaten (Ohio State University)

DPF15.pdf

175 Exotic hadron spectroscopy in LHCb

Analysis of the 3.0 fb-1 of data collected with the LHCb yielded several important results on exotic hadron candidates including $X(3872)$ and $Z(4430)^+$. The new results will be presented, including the analysis of orbital angular momentum in $X(3872)$ decay to $\pi^+\pi^- J/\psi$ and reanalysis of its quantum numbers.

Speaker: Nathan Philip Jurik (Syracuse University (US))

DPF_ExoticHadrons.pdf

176 Searches for the exclusive double diffractive Higgs

The exclusive Higgs could be a clean channel to study Higgs properties. The most popular theoretical model for the exclusive Higgs predicts a total cross section of 3 fb at p-p 8 TeV collision energy. This study summarizes a search for the exclusive Higgs boson using ATLAS 8 TeV data, using the channel in which the Higgs decays to a pair of W bosons with different flavor leptons in the final state. Selection criteria are developed to isolate exclusive processes from inclusive processes. Selection criteria that isolate Higgs-like events that are inherited from previous Higgs searches are utilized. A limit of 770 fb on the total cross section of the exclusive Higgs production is obtained.

Speaker: Last Feremenga (University of Texas at Arlington)

dpfMeeting.pdf

177 Exotic and Charmonium(-like) states at BESIII

The BESIII Experiment at the Beijing Electron Positron Collider (BEPCII) has accumulated the world's largest samples of direct $e^+e^-$ collisions in the tau-charm region. From the collected samples, which include $e^+e^-$ annihilations at J/$\psi$, $\psi$(2S), $\psi$(3770) peaks and in the region from 4 GeV to 4.6 GeV, BESIII has produced many new physics results in the spectroscopy, transitions, and decays of charmonium(-like) states. This talk will cover the latest results over a wide range of topics from radiative and hadronic transitions among charmonium states, as well as the productions and decays of the $XYZ$ states.

Speaker: Dr Peilian, on behalf of the BESIII collaboration LIU (Institute of High Energy Physics Chinese Academy of Sciences, China)

DPF2015_BESIIIXYZ.pdf

178 Measurement of low pT D+ meson production cross section at CDF

We present a measurement of the production cross section of the D+ mesons in proton-antiproton collisions at 1.96 TeV center-of-mass energy, using the full data set collected by the CDF experiment at the Tevatron collider during Run II. The measurement is performed in a yet unexplored low transverse momentum range, down to 1.5 GeV/c, using events collected with the "zero bias" and "minimum bias" triggers. The actual QCD theory cannot predict the behavior of the strong interactions in the low transferred 4-momentum region because in these kinematic conditions the strong coupling constant is of the order of the unity. Thus, a perturbative expansion is no longer permitted. At present, several phenomenological models have been proposed, but they are able to describe only few aspects of the observed physical quantities and not their whole complexity. Experimental results in this conditions are then crucial to predict new QCD models. The measurement of the differential cross section at low pT plays an important role in this context allowing to refine the actual knowledge. After the shutdown of the Tevatron, this is very likely going to remain a unique measurement because of the initial state (proton-antiproton) and center-of-mass energy.

Speaker: Luigi Marchese (Fermilab)

179 Measurement of Correlation of Lambda Pairs with the ATLAS Detector

We report here the first observation of a direct spin correlation between pairs of like-type and unlike-type $\Lambda$ hyperons produced in inclusive processes at the LHC. The analysis is based on hyperon pairs collected at the ATLAS experiment from pp collisions at a center-of-mass energy of 7 TeV in 2010. A depletion of like-type events when compared to unlike-type events is observed for $Q<3$ GeV and is known to be the effect of the Fermi-Dirac statistics between identical fermions. The correlation parameter of the decay angles for decay $\Lambda \rightarrow p \pi^-$ ($\bar{\Lambda} \rightarrow \bar{p} \pi^+$) is extracted for data as a function of $Q$ using a data-driven reference sample in which uncorrelated hyperon pairs are selected from different events in the same data sample. No spin correlation has been observed for unlike-type events, while deviation from zero is observed for like-type events in the same region where depletion of differential cross-section occurs.

Speaker: Hok Chuen Cheng (University of Michigan (US))

DPF2015_LamPairCorr_HokChuenCheng.pdf

Top Physics

180 Observation of ttZ and measurement of ttW at CMS

New measurements of top quark pair production in association with a W or Z boson are presented, using 19.5 fb−1 of 8 TeV pp collision data collected by the CMS experiment at the CERN LHC. Final states with opposite-sign, same-sign, three, and four charged leptons plus b-tagged jets are examined. Signal ttW and ttZ events are identified by reconstructing the top quark pair, yielding the most sensitive and precise measurements of these processes to date. New limits are also placed on five anomalous dimension-six operators which would affect the ttW and ttZ cross sections.

Speaker: Andrew Brinkerhoff (University of Notre Dame (US))

August_05_ttV_DPF_v2.pdf

181 Measurement of the production cross sections of top quark pairs in association with a W or Z boson using proton-proton collisions at $\sqrt{s}$=8 TeV with the ATLAS detector

We present a measurement of the production cross sections of top quark pairs in association with a W or Z boson. The measurement uses 20.3 $fb^{-1}$ of data from proton-proton collisions at $\sqrt{s}$=8 TeV recorded by the ATLAS detector at the LHC at CERN. Four different final states are considered: two opposite-sign leptons, two same-sign leptons, three leptons, and four leptons. We report the $t\bar{t}+Z$ and $t\bar{t}+W$ signal strength with respect to the Standard Model prediction, as well as the corresponding signal significance.

Speaker: Chen Zhou (Duke University (US))

chen.pdf

182 Measurement of tt-gamma production cross section at CMS

We present a measurement of the production cross-section of top-quark pairs in association with a photon in pp collisions at center-of-mass energy of 8 TeV. The data was recorded at the CMS experiment, corresponding to 19.7 fb-1 integrated luminosity. The measurement is performed in dilepton and lepton+jets final states. Data-driven methods are used to estimate the photon identification efficiency and purity. The measured cross-section agrees with the standard model expectation.

Speaker: Andrew Ivanov (Kansas State University (US))

183 Search for Standard Model Production of Four Top Quarks

A search is presented for standard model (SM) production of four top quarks in pp collisions at the LHC. Using Run-1 data corresponding to an integrated luminosity of 19$fb^{-1}$, a combination of kinematic reconstruction and multivariate techniques is used to distinguish between the small signal ($\sigma^{SM}_{t \bar{t} t \bar{t}} \sim 1 fb$) and backgrounds in the lepton + jets channel. The data are consistent with expectations for SM background and signal, and an upper limit of 32 fb is set at a 95% confidence level on $\sigma^{SM}_{t \bar{t} t \bar{t}}$, where a limit of 32 ± 17 fb is expected. Further comments on preparation and prospects for Run-2 are also presented.

Speaker: Jesse Alan Heilman (University of California Riverside (US))

JHeilman_APD_DPF_2015_v5.pdf

DPF Exec Committee

Convener: nicholas hadley

Thursday 6 August

07:30 Breakfast

Session I-C

Convener: David Cinabro (Wayne State University)

184 Quark Flavor Physics

Processes involving quark flavor changes are sensitive probes of additional short-range interactions. Such processes can also be used to search for low-mass hidden-sector bosons. I will summarize the current state of the field, focusing on the stringent model-independent constraints placed on physics at high mass scales. A few intriguing anomalies will also be highlighted.

Speaker: J Michael Williams (Massachusetts Inst. of Technology (US))

Williams_DPF2015.pdf

185 Heavy-ion collisions - hot QCD in laboratory

High energy heavy-ion collisions provide a unique opportunity to study the hot and dense QCD medium, the quark-gluon plasma (QGP) - a state of matter that possibly existed some microseconds after the Big Bang. Relativistic hydrodynamics calculations describing the correlations of particles produced in heavy-ion collisions tell that the QGP is a strongly coupled liquid characterized by the smallest ratio of shear viscosity to entropy density from all known materials - QGP is an almost ideal liquid. On the other hand, such a medium is opaque to high energy jets and heavy-quarks, and it is hot enough to dissolve quarkonia states. A review of the results obtained with collisions of heavy-ions at the Large Hadron Collider and Relativistic Heavy Ion Collider will be given. In addition, the recent, intriguing findings of collective particle production found in much smaller collision systems such as proton-lead, deuteron-gold, and even proton-proton will be discussed.

Speaker: Mateusz Ploskon (Lawrence Berkeley National Lab. (US))

heavy-ions_ploskon.pdf

186 Cosmology Experiment (DM, Collider)

Speaker: Jocelyn Monroe (Royal Holloway)

DPF2015_jmonroe.pdf

10:15 Cafe Break

Session II-C

Convener: Steven Ahlen (Boston University (US))

187 Beyond the WIMP: New Detectors for New Dark Matter Ideas

I review the current status of the search for dark matter, focused on the Weakly Interacting Massive Particle (WIMP) paradigm. I then discuss how this paradigm is becoming increasingly squeezed by experiment. I argue that well-motivated models are currently missed by the existing suite of experiments, and discuss current efforts to broaden the search for the nature of the dark matter.

Speaker: Kathryn Zurek (University of Michigan)

15_DPF_A2.pdf

188 The State of Dark Energy in 2015

I will present our state of knowledge on dark energy from baryon acoustic oscillation (BAO) and cosmic microwave background (CMB) experiments. The BOSS experiment reaches near the cosmic variance limit of the BAO technique at low redshift, in the epoch of acceleration. Future experiments will focus on higher redshifts where greater precision is possible for dark energy constraints and for measuring the imprints of non-gaussianity from early-universe inflation.

Speaker: David Schlegel (Lawrence Berkeley National Lab)

DPF_schlegel_06aug2015.pdf

DPF_schlegel_06aug2015.pdf

189 Exascale and Exabytes: Future directions in HEP Software and Computing

Current and future HEP experiments will record and simulate larger and larger volumes of data, some going well beyond the petabyte scale. To succeed, analysts will need to master modern software and computing technologies to extract physics results from these large datasets. I will review current trends for HEP software and computing and show possible future directions for data analysis in the exabyte era.

Speaker: Oliver Gutsche (Fermi National Accelerator Lab. (US))

150806 - Oliver Gutsche - DPF2015 - Future directions in HEP Software and Computing.pdf

12:30 Lunch (box lunch provided)

Lunch and Learn: How to Engage the Public: (box lunch provided)

Conveners: Don Lincoln (Fermilab), Nicole Michelotti (University of Michigan)

DOE Program: Energy Frontier

Convener: Abid Patwa (U.S. Department of Energy)

190 Energy Frontier

Speaker: Abid Patwa (U.S. Department of Energy)

DPF_2015_Energy_Frontier_August2015_FINAL.pdf

AstroParticle, Cosmology, Dark Matter Searches, and CMB

Convener: Marilena Loverde (University of Chicago)

191 Neutrino Dark Matter in the Higgs triplet model

In this work we analyze the effects of introducing vectorlike leptons in the Higgs triplet model to provide a scenario that can explain both neutrino masses and provide a Dark Matter candidate, two essential shortcomings of the Standard Model. We investigate constraints, including the invisible decay width of the Higgs boson and the electroweak precision variables, and impose restrictions on model parameters. We analyze the effect of the relic density constraint on the mass and Yukawa coupling of dark matter. We also calculate the cross sections for indirect and direct dark matter detection and show our model predictions for the neutrino and muon fluxes from the Sun, and the restrictions they impose on the parameter space. With the addition of vectorlike leptons, the model is completely consistent with dark matter constraints, in addition to improving electroweak precision and doubly charged mass restrictions, which are rendered consistent with present experimental data.

Speaker: Sahar Bahrami (Concordia University)

SBAHRAMI_DMInTheHTM-1.pdf

192 Soft-collinear effective theory for heavy WIMP annihilation

I report status and recent results in the theory and phenomenology of heavy WIMP annihilation signals.

Speaker: Mikhail Solon (University of Chicago)

193 Cosmology of Massive Gravity

The quest for a stable, compelling, cosmology of massive gravity. I will introduce some of the everyday tools of massive (bi)gravity and then show how, confronted with stability and observational requirements, one may employ them to place strong constraints on the parameters space of the theory.

Speaker: Dr Matteo Fasiello (Stanford University)

Fasiello_DPF15.pdf

194 Optimized evaluation approach for inflationary power spectra

We develop optimized approaches for the evaluation of curvature and gravitational wave power spectra from single field inflation using the generalized slow-roll approach to extend the validity of the standard slow-roll approximation. Since the deviations from scale-invariance are only assumed to be small in amplitude not in temporal frequency, our approach applies to models with features in the potential.

Speaker: Dr Hayato Motohashi (University of Chicago)

2015.08.06 DPF.pdf

195 Gauge and fermion preheating and the end of axion inflation

Axions are attractive candidates for theories of large-field inflation that are capable of generating observable primordial gravitational wave backgrounds. These fields enjoy shift-symmetries that protect their role as inflatons from being spoiled by coupling to unknown UV physics. This symmetry also restricts the couplings of these axion fields to other matter fields. At lowest order, the only allowed interactions are derivative couplings to gauge fields and fermions. These derivative couplings lead to the biased production of fermion and gauge-boson helicity states during and after inflation. I will describe some recent work on preheating in axion-inflation models that are derivatively coupled to Abelian gauge-fields and fermion axial-currents. For an axion coupled to U(1) gauge fields it is found –analytically and numerically- that preheating is efficient for a wide range of parameters. In certain cases the inflaton is seen to transfer all its energy to the gauge fields within a few oscillations. In most cases, three-dimensional lattice simulations showed that the gauge fields on sub-horizon scales end preheating in an unpolarized state due to the existence of strong rescattering between the inflaton and gauge-field modes. The conclusions are qualitatively similar for quadratic and monodromy axion potential, with the additional formation of oscillons for the latter. Coupling an axion to Majorana fermions leads to biased production of fermion helicity-states which can have interesting phenomenological implications for leptogenesis.

Speaker: Evangelos Sfakianakis (University of Illinois at Urbana-Champaign)

APS_2015.pdf

Neutrino Physics

Conveners: Daniel Hernandez, Irina Mocioiu (Pennsylvania State University), Lindley Winslow (Massachusetts Institute of Technology), Lisa Kaufman (Indiana University)

196 Elementary target data and precision neutrino-nucleus cross sections

A new determination of the axial-vector form factor from neutrino-deuteron scattering data is presented. Implications for the extraction of fundamental neutrino properties at long baseline experiments are discussed.

Speaker: Richard Hill

hill_dpf_nu.pdf

197 Measurement of the Charged Current Electron Neutrino Interaction Rate on Water with the T2K Pi-zero Detector

The T2K experiment is a long-baseline neutrino experiment designed to measure $\nu_{\mu } \longrightarrow \nu_{\mu}$ and $\nu_{\mu } \longrightarrow \nu_{e}$ oscillation. With the recent firm establishment of $\nu_{e}$ appearance by T2K, future precision $\nu_{e}$ appearance measurements can be used to explore CP violation in neutrino interactions. However such an exploration requires detailed understanding of the $\nu_{e}$ ($\bar{\nu}_{e}$) interactions, as well as contamination of $\nu_{e}$ ($\bar{\nu}_{e}$) in the $\nu_{\mu}$ ($\bar{\nu}_{\mu}$) beam. To this end, the T2K off-axis $\pi^{0}$ detector (P0D) has been used to measure $\nu_{e}$ charged current interaction rates on water. We present the details of the analysis, including the selection criteria and the systematic uncertainties. Finally, we will discuss prospects for the charged current $\bar{\nu}_{e}$ interaction rate measurement with the P0D.

Speaker: Jay Hyun Jo (Stony Brook University)

JHJ_DPF_08062015.pdf

198 Measurement of the $\nu_\mu$ Charged Current Quasielastic Scattering Cross Section on Water with the T2K Off-Axis Near Detector

The T2K experiment is a long-baseline neutrino oscillation experiment that uses an off-axis neutrino beam from the J-PARC accelerator to measure $\nu_e$ appearance and $\nu_\mu$ disappearance at Super-Kamiokande, 295 km away. The $\nu_\mu$ disappearance analysis at Super-Kamiokande relies on measurements of charged current quasielastic (CCQE) scattering events on water. The ND280 off-axis near detector is used to constrain the neutrino flux at Super-Kamiokande and also to measure a variety of neutrino cross sections. This talk will present ongoing work toward measuring the cross section of $\nu_\mu$ CCQE-like scattering events on water using ND280. The selection identifies events with a muon and any number of nucleons but no pions. While much of ND280 is composed of bars of scintillating plastic, the $\pi^0$ Detector (PØD), one of the subdetectors comprising ND280, contains target volumes that may be filled with water or left as empty air volumes. Our analysis will apply an iterative Bayesian unfolding method to reconstruct the momentum and angle distribution of selected muons in CCQE-like events for each PØD water target configuration. We plan to extract the cross section on water alone by subtracting the result with empty water targets from the result with filled water targets.

Speaker: Jeremy Lopez (University of Colorado at Boulder)

T2KNumuCCQE.pdf

199 HARP targets $\pi^{+}$ production measurements and $\nu_\mu$ flux for MiniBooNE

The prediction of the muon neutrino flux from a 71.0 cm long beryllium target for the MiniBooNE experiment is based on a measured pion production cross section which was taken from a thin beryllium target (2.0 cm thick - $5 \%$ nuclear interaction length) in the Hadron Production (HARP) experiment at CERN. To verify the extrapolation to our longer target, HARP also measured the pion production from 20.0 cm and 40.0 cm beryllium targets. The measured production yields, ${d^{2} N^{\pi^{+}}(p,\theta)}/{dp d\Omega}$, on targets of $50 \%$ and $100 \%$ nuclear interaction lengths in the kinematic rage of momentum from 0.75 GeV/c to 6.5 GeV/c and the range of angle from 30 mrad to 210 mrad are presented along with an update of the thin target cross sections. The best fitted modified Sanford-Wang (SW) model parameterization for updated thin beryllium target $\pi^{+}$ production cross section is presented. Yield measurements for all three targets are also compared with that from the Monte Carlo predictions in the MiniBooNE experiment for different SW parameterization. The comparisons of $\nu_\mu$ flux predictions for updated SW model is presented.

Speaker: Don Athula Wickremasinghe for MiniBooNE Collaboration (University of Cincinnati)

DPF2015_athula.pdf

EWK and Higgs Sector: Electroweak Measurement

Convener: Sara Lynn Dawson (Brookhaven National Laboratory (US))

200 Physics prospects of the ZZ production measurements with the ATLAS experiment at LHC RUN2

I report physics prospects of the ZZ production measurements with the ATLAS experiment using 10 fb-1 of 13-TeV proton-proton collision data to be collected in the LHC Run 2. First look at early Run 2 data, if available, will also be presented.

Speaker: Dr Cong GENG (USTC/University of Michigan)

DPF2015_Cong_5.pdf

DPF2015_Cong_5.pptx

201 Measurement of the Muon Charge Asymmetry for W Bosons Produced in Inclusive pp → W(μν) + X at √s = 8 TeV

Measurement of the Muon Charge Asymmetry for W Bosons Produced in Inclusive pp → W(μν) + X at √s = 8 TeV are presented. The data sample corresponds to an integrated luminosity of 18.8 inverse femtobarns recorded with the CMS detector at the LHC. With a sample of more than a hundred million W to mu nu events, the statistical precision is greatly improved in comparison to previous measurements. These new results provide additional constraints on the parton distribution functions of the proton.These measurements are used together with the cross sections for inclusive deep inelastic ep scattering at HERA in a next-to-leading-order QCD analysis. The determination of the valence quark distributions is improved.

Speaker: Hasan Ogul (University of Iowa (US))

DPF_2015.pdf

202 Improving parton distribution uncertainties in a W mass measurement at the LHC

We reexamine the dominant contribution of parton distribution function (PDF) uncertainties to the W mass measurement, and determine their contribution is $\pm 39(30)$ MeV when running the Large Hadron Collider at 7(13) TeV. We find that spurious correlations in older PDF sets led to over-optimistic assumptions regarding normalization to Z observables. In order to understand the origin of the large uncertainties we break down the contribution of the PDF errors into effects at the hard matrix element level, in showering, and in sensitivity to finite detector resolutions. Using CT10, CT10W, and charm enhanced PDF sets in comparison to older PDF sets, we develop a robust analysis that examines correlations between transverse mass reconstructions of W and Z decays (scaled by 1/cos $\theta_W$) to leptons. We find that central leptons ($|\eta_l| < 1.3$) from $W^-$ and $Z$ bosons carry the most weight in reducing the PDF uncertainty, and estimate a PDF error of $^{+10}_{-12}$ MeV is achievable in a W mass measurement at the LHC. Further reductions of the W mass uncertainty will require improved fits to the parton distribution functions.

Speaker: Zack Sullivan (Illinois Institute of Technology)

ZS_DPF15.pdf

Quark and Lepton Flavor Physics

Conveners: J Michael Williams (Massachusetts Inst. of Technology (US)), Jure Zupan (University of Cincinnati)

203 Measurement of forward-backward asymmetries in B+, Λb, and Λ production in pp ̄ collisions at √s=1.96 TeV

Speakers: Peter Garbincius (Fermilab), Peter H Garbincius

Garbincius_DPF2015_AFB-5.pdf

204 Measurement of the Lambdab polarization and decay helicity amplitu

Speaker: Dongliang Zhang (University of Michigan (US))

Atlas_LambdaB_DongliangZhang.pdf

205 Double Quarkonium Production at CMS

Speaker: Maksat Haytmyradov (University of Iowa (US))

206 Exclusive semileptonic B decays to a D or D* meson and one or two pions

Speaker: Bob Kowalewski (University of Victoria (CA))

Dpipilnu.pdf

BSM Physics

Conveners: Kevin Black (Boston University), Nathaniel Craig (UC Santa Barbara), Rouven Essig

207 Dark Matter search in ATLAS in the H -> two photons + MET channel: Run 1 results and Run 2 prospects

Mono-objects produced in association with large missing transverse momentum (MET) enable fairly model-independent searches for dark matter candidates. Following the discovery of a Higgs boson near 125 GeV, mono-Higgs channels provide very interesting final states for dark matter search. This talk presents an analysis in the H -> two photons + MET final state in ATLAS using 20 fb-1 of 8 TeV data. Results are interpreted as model-independent exclusion limits on the production cross section of non-SM states, as well as exclusion of parameter spaces of simplified models of dark matter production. Also presented is a strategy for dark matter searches in mono-Higgs final states with LHC Run 2 data, as recommended by the LHC Dark Matter Forum.

Speaker: Lashkar Kashif (University of Wisconsin)

Lashkar_monoH_yy_DPF2015.pdf

208 Search for Dark Matter produced in association with a Higgs Boson decaying to two bottom quarks in s= 8TeV pp collisions with the ATLAS detector

This talk will present a search for dark matter pairs produced in association with a Higgs boson decaying into two bottom quarks at the LHC, based on 20 fb−1 of pp collision data collected by the ATLAS experiment at 8 TeV. Events with large missing transverse momentum are selected when produced in association with high momentum jets, of which at least two are identified as jets containing b-quarks consistent with those from a Higgs decay. The results are interpreted through a simplified model (2HDM) where a Higgs-doublet is produced via Z’ decay, and the heavy higgs decays into a pair of dark matter particles. Results are presented in terms of the mass of the Z’ particle and the heavy pseudoscalar higgs. Results are also presented on the mass scale of effective field theories that describe scalar and tensor interactions between dark matter and Standard Model particles. Additional interpretations are shown using simplified models where the Higgs is produced through Higgs-strahlung of the Z’. The fiducial cross section will also be presented for this analysis.

Speaker: Yangyang Cheng (University of Chicago (US))

ycheng_monoHbb_dpf2015.pdf

209 Search for a light dark sector particle at LHCb

There is strong evidence that the Standard Model of particle physics is incomplete. The lack of evidence for any new particles had renewed interest in theories postulating the existence of a Dark Sector. The precise manifestation of these particles is entirely unknown, but at low masses a dominant decay channel would be into a dimuon pair. To that end, a search for a dark sector particle, $\chi$, is performed by studying the decay $B^0 \rightarrow K^*(892)^0\mu^+\mu^-$ and $B^+ \rightarrow K^+\mu^+\mu^-$ for candidates consistent with $\chi \rightarrow \mu^+\mu^-$. Limits on the branching fraction of both decay modes are set, as functions of both the mass and \chi lifetime, in a fully frequentist manner.

Speaker: Mr Andrea Mauri (University of Zurich)

DPF_DarkBoson.pdf

210 Search for long-lived, weakly-interacting particles that decay to displaced hadronic jets in proton-proton collisions at $\sqrt{s}=8$ TeV with the ATLAS detector

Many new physics models predict the existence of neutral, weakly interacting, long-lived particles that could decay within the detector volume, producing a distinctive experimental signature. Results are presented for a search for these particles, using techniques for reconstructing displaced decays to hadronic jets in the inner tracking detector and muon spectrometer. The search is performed using proton-proton collision data at $\sqrt{s} =8$ TeV collected by the ATLAS detector in 2012, corresponding to a total integrated luminosity of 20.3 fb$^{−1}$. Signal events are required to have at least two reconstructed decay vertices. Results are interpreted in terms of stealth supersymmetry (SUSY) models, and Hidden Valley scenarios with a scalar boson or Z' boson mediator.

Speaker: Preema Rennee Pais (University of Massachusetts (US))

PreemaPais_DPF2015_08062015.pdf

211 Search for new physics in the low MET monophoton channel with the CMS Detector

With the recent discovery of the Higgs boson at the Large Hadron Collider, the goals of the Compact Muon Solenoid (CMS) Experiment are now focused on probing for new physics beyond the standard model. The final state consisting of a low transverse energy photon and low missing transverse energy (MET), also called the “monophoton” final state, can be used to constrain a variety of extensions of the standard model, including supersymmetry. I present a search for new physics in this low MET monophoton channel using 7.3/fb of 8 TeV LHC collected with the CMS detector, as part of our parked data program. This analysis extends the high-energy single-photon searches to a lower-energy regime. In the absence of deviations from the standard model predictions, limits are set on the production cross section of exotic decays of the Higgs boson. In addition, we present model independent limits as a function of MET requirement.

Speaker: Toyoko Orimoto (Northeastern University (US))

toyoko_monophoton_dpf_2015_final.pdf

212 Search for ttbar Resonances at CMS

We present the legacy search for resonant top quark pair production, using proton-proton collision data collected with the CMS detector at the CERN LHC at a center-of-mass energy of 8 TeV. The search is performed by measuring the invariant mass distribution of the top-quark pair and testing for deviations from the expected Standard Model background. Final states with zero, one or two leptons are considered and the selection is optimized accordingly, taking into account the high Lorentz boost of the top quarks at high invariant masses. The results are presented in the form of mass and cross section limits on three types of new physics models: both a narrow and wide Z' boson as well as a Randall-Sundrum Kaluza-Klein gluon. These boosted top quark signatures can be identified and reconstructed through the use of jet substructure and subjet b-tagging algorithms. Thus, we further present studies of boosted top-quark tagging at CMS for Run 2 collision events at 13 TeV center-of-mass energy, including new improvements to the top-tagging algorithms.

Speaker: Justin Pilot (University of California Davis (US))

DPF_JPilot.pdf

Accelerators, Detectors, Computing

Conveners: Rainer Bartoldus (SLAC), Torre Wenaus (Brookhaven National Laboratory (US))

213 CMS Software and Computing: Ready for Run 2

In Run 1 of the Large Hadron Collider, software and computing was a strategic strength of the Compact Muon Solenoid experiment. The timely processing of data and simulation samples and the excellent performance of the reconstruction algorithms played an important role in the preparation of the full suite of searches used for the observation of the Higgs boson in 2012. In Run 2, the LHC will run at higher intensities and CMS will record data at a higher trigger rate. These new running conditions will provide new challenges for the software and computing systems. Over the two years of Long Shutdown 1, CMS has built upon the successes of Run 1 to improve the software and computing to meet these challenges. In this presentation we will describe the new features in software and computing that will once again put CMS in a position of physics leadership.

Speaker: Kenneth Bloom (University of Nebraska (US))

dpf_cms_computing_150806.pdf

214 Software and Physics Simulation at Belle II

The Belle II experiment at the SuperKEKB collider in Tsukuba, Japan, will start physics data taking in 2018 and will accumulate 50/ab of e+e- collision data, about 50 times larger than the data set of the earlier Belle experiment. The new detector will use GEANT4 for Monte Carlo simulation and an entirely new software and reconstruction system based on modern computing tools. Examples of physics simulation including beam background overlays will be described

Speaker: Prof. Doris Kim (Soongsil University)

DPF_2015_dorisykim_v2.pdf

215 GRID computing at Belle II

The Belle II experiment at the SuperKEKB collider in Tsukuba, Japan, will start physics data taking in 2018 and will accumulate 50/ab of e+e- collision data, about 50 times larger than the data set of the earlier Belle experiment. The computing requirements of Belle II are comparable to those of a RUN I high-p_T LHC experiment. Computing will make full use of the GRID in North America, Asia and Europe and high speed networking. Results of an initial MC simulation campaign with 5 ab^-1 equivalent luminosity will be described.

Speaker: Vikas Bansal (Pacific Northwest National Laboratory)

VikasBansal_talk_DPF_2015.pdf

VikasBansal_talk_withErrata_DPF_2015 .pdf

216 Code Management in the ATLAS Collaboration

The ATLAS offline software code base includes 2200 packages with 4 million C++ and 1.4 million python lines created by more than 1000 developers. Active software development continues since the collaboration creation and will continue to move forward to meet the requirements of new physics analysis variants and be abreast of evolving changes in computing technologies. The ATLAS offline code management system is the powerful, flexible framework for processing new package versions requests, probing code changes in the Nightly Build System, migration to new platforms and compilers, deployment of production releases for worldwide access, and supporting physicists with tools and interfaces for efficient software use. The presentation describes the flexible code management tools and techniques that are developed and supported by the ATLAS Software Infrastructure Team (ATLAS Tag Collector, Nightly Control System, ATN and RTT testing frameworks), in particular, how multiple development branches are validated and merged in creation of production releases and how upgrades to new software tools, platforms and compilers are performed. It also provides information on the ways of communications between physicists and software professionals and the process of software validation. In addition, future ATLAS Software Infrastructure development plans are presented.

Speaker: Dr Alexander Undrus (BNL)

ATLAS_CODE_MNGMT_DPF2015.pdf

217 The HEP Software Foundation

The HEP Software Foundation (HSF) has recently been established as a HEP community organization to facilitate coordination and common efforts in HEP software and computing internationally. The objectives of the HSF include the sharing of expertise, raising awareness of existing software and solutions, catalyzing new common projects, aiding developers and users in creating and using common software, supporting career development for software and computing specialists, and facilitating connections with other science fields. This talk will describe the HSF and how you can become involved. Learn more at [hepsoftwarefoundation.org][1]. [1]: http://hepsoftwarefoundation.org

Speaker: Torre Wenaus (Brookhaven National Laboratory (US))

HSF-DPF-Wenaus-20150806.pdf

218 New Developments in Multivariate Machine Learning Methods and their Applications in HEP

Over the past 25 years, Multivariate Analysis (MVA) methods have gained gradual acceptance and are now considered as state of the art methods in high energy physics data analyses. From precision measurements of the top quark mass and other properties at the Tevatron in the mid-90’s to the Higgs discovery in 2012 at the LHC, and in a variety of applications such as object ID and energy corrections, MVA methods have provided huge benefits in the physics results extracted in HEP. I will discuss some new developments in multivariate machine learning methods as well as some older, untapped techniques and their potential applications in the challenging data analysis tasks in LHC Run 2 and beyond.

Speaker: Pushpalatha Bhat (Fermi National Accelerator Lab. (US))

PushpaBhat_DPF2015_MVA.pdf

PushpaBhat_DPF2015_MVA.pptx

219 Data Preservation at the Fermilab Tevatron

The Fermilab Tevatron collider's data-taking run from 2001 to 2011 yielded a dataset with rich scientific potential. The CDF and D0 experiments each have nearly 10 PB of collider and simulated data stored on tape. A large computing infrastructure consisting of tape storage, disk cache, and distributed grid computing for physics analysis with the Tevatron data is present at Fermilab. The Fermilab Run II data preservation project intends to keep this analysis capability fully sustained through the year 2020 or beyond. We are implementing a system that utilizes virtualization, automated validation, and new standards in both software and data storage technology, and includes the ability to generate new Monte Carlo simulation. It also leverages resources available from currently-running experiments at Fermilab. We will present the status, benefits, and challenges of data preservation efforts at the Tevatron.

Speaker: Bo Jayatilaka (Fermi National Accelerator Lab. (US))

dpf15-dp-jayatilaka.pdf

QCD and Heavy Ions

Convener: Aaron Angerami (Columbia University (US))

QCDTevDPF2015.pdf

220 Model Independent Analysis of the Proton Magnetic Radius

The Proton is a fundamental constituent of matter. In contrast to other fundamental particles like the electron, it is an extended object and has a finite size that can be inferred with some degree of accuracy from several measurements. The electric radius can be extracted from electron-proton scattering experiments,(r_E^p=0.871±0.009 fm) and Lamb shift in Muonic Hydrogen (r_E^p=0.84184±0.0006 fm). The reason for the discrepancy between these values is still unknown. In the literature there also exist several values of the proton magnetic radius extracted using several model-dependent methods. We use constraints from the analytic behavior of the form factors to determine the proton magnetic radius in a model-independent way. Using existing datasets of electron-proton scattering we find r_M^p=〖0.91〗_(-0.06)^(+0.03)±0.02 fm. When we include electron-neutron scattering data and pion data, we find r_M^p=〖0.87〗_(-0.05)^(+0.04)±0.01 fm and r_M^p=〖0.87〗_(-0.02)^(+0.02) fm respectively. We also extracted the neutron magnetic radius as r_M^n=〖0.89〗_(-0.03)^(+0.03) fm combining all three datasets.

Speaker: Joydeep Roy (Wayne State University)

APS DPF 2015_Roy.pdf

221 Recent results on low-energy e+e- annihilation into hadrons with initial state radiation with the BABAR detector

The BABAR Collaboration has an extensive program of studying hadronic cross sections at low-energy e+e- collisions, accessible at the center-of-mass energy of about 10.6 GeV via initial-state radiation. Our measurements allow significant improvements in the precision of the predicted value of the muon anomalous magnetic moment. These improvements are necessary for shedding light on the current ~3.5 sigma difference between the predicted and the experimental values. We report here the most recent results on several processes, including e+e- -> pi+pi-pi0pi0, e+e- -> K_S K- pi+ pi0 and e+e- -> K_S K- pi+ eta. The cross section is measured up to 4.5 GeV and the internal structure of the final hadronic states is studied. With the same technique we have also studied the charge asymmetry in the e+e- -> pi+pi- and mu+mu- reactions. The measured asymmetry is compared with QED predictions for muons, and theoretical models for pions. A clear interference pattern is observed for pions in the vicinity of the f2(1270) resonance.

222 Measurement of Collins asymmetries for kaons and pions in e+e- annihilation at BABAR

Inclusive hadron production cross sections and angular distributions in e+e- collisions shed light on fundamental questions of hadronization and fragmentation processes. We present measurements of the so-called Collins azimuthal asymmetries in inclusive production of hadron pairs, in the e+e- -> h1 h2 X annihilation process, where the two hadrons (either kaons or pions) are produced in opposite hemispheres. The data collected by the BABAR detector allows the determination of the Collins fragmentation function as a function of hadron fractional energies and transverse momenta for the up, down and strange quarks, and can be combined with semi-inclusive deep-inelastic-scattering data to extract the transversity distribution function, which is the least known leading-twist component of the QCD description of the partonic structure of the nucleon.

Speaker: David Norvil Brown (University of Louisville (US))

DNB_CollinsTalkDPF2015_v1.pdf

223 Study of inclusive charmonium production in e+e- annihilation and B decays at BABAR

In an e+e- B factory charmonium states can be produced through different mechanisms, as in e+e- annihilation, with double charmonium production, and in B-meson decays. Prompt production of J/psi or psi(2S) in association with a second charmonium state has been observed by both the BaBar and Belle experiments in e+e- annihilation at a center-of-mass energy of 10.58 GeV. These processes provide an opportunity to study both perturbative and non-perturbative effects in QCD and to search for new charmonium states recoiling against the reconstructed J/psi or psi(2S). We present a study of such events using the full BaBar dataset. We also present measurements of absolute branching fractions of the two-body decays of B mesons B( B -> K Xcc), where Xcc is a charmonium state. In fact, in events where one B is fully reconstructed, the charmonium spectrum can be observed in an unbiased way, looking at the distribution of the K momentum in the recoiling B rest frame.

Speaker: Jacob Berg (University of Louisville)

JWB_DPF2015_0806v2.pdf

15:30 Cafe Break

DOE Program: Cosmic Frontier

Convener: Kathy Turner (DOE)

224 Cosmic Frontier

Speaker: Kathleen Turner (US Department of Energy)

2015 August - DPF meeting Cosmic Frontier SHOWN.pdf

2015 August - DPF meeting Cosmic Frontier SHOWN.pptx

AstroParticle, Cosmology, Dark Matter Searches, and CMB

Convener: Marilena Loverde (University of Chicago)

225 Contribution of Dark Matter Annihilations to the Low-Redshift Metagalactic Ionization Rate

Dark matter annihilations can inject a significant amount of energy into the visible sector following the clustering of Dark Matter (DM) into halos at late times. Motivated by the DM interpretation of the gamma-ray excess in the inner Milky Way, we study the diffusive escape of the electrons and positrons produced by DM annihilations from the host halo, and the subsequent in-situ upscattering of the CMB photons in the IGM. This ICS emission component contributes to the cosmic UV background and becomes an efficient source of heating and ionization of the Lyman-alpha forest at low redshift, when the contribution from the star-forming galaxies and quasars is expected to decline. We further investigate its relevance to the recent mismatch (Kollmeier et al. 2014) between the expected and observed number of Lyman-alpha absorbers at low-redshift. Regardless of the relevance to this crisis, the prediction of a ~ GeV electron-positron population in the IGM can put constraints on the DM annihilation cross section, considering the well-measured X-ray background.

Speaker: Tansu Daylan (Harvard University)

20150806_dpf2015.pdf

226 How dark matter conspires to facilitate baryogenesis at the electroweak scale

The standard model is insufficient to explain two a-priori unrelated problems in modern physics, the nature of the cosmological dark matter (DM) and baryon asymmetry. The latter has long been sought to be explained by baryogenesis at the electroweak scale, which, however, has been proven to be very difficult for a Higgs boson mass as high as 125 GeV. In this presentation, we will explore a scenario by which those two problems may be solved at once. We consider a variant of 'hidden sector DM', namely ultralight, bosonic particles which go into a coherent ground state almost immediately after their birth upon inflaton decay. The DM is supposed to be charged under a U(1)-symmetry, with the charge being the (conserved) DM abundance. The cosmic evolution of this complex scalar field dark matter (SFDM) has been studied in the past, where it has been found that the expansion history can be in accordance with LCDM, if the fundamental parameters of the model, boson mass and self-interaction, are appropriately constrained by observations. In particular, SFDM morphes from cold DM to relativistic DM when approaching the early Universe, where its contribution to Neff - the extra relativistic degrees of freedom - has to be properly contrained by Big Bang nucleosynthesis and the primordial gravitational wave background from inflation. In our model, SFDM is the dominant cosmic component in the Universe after reheating, since its early evolution is driven by its kinetic energy term, rendering its equation-of-state to be that of 'maximal stiff matter', when w=p/rho ~ 1. The associated expansion rate is many orders of magnitudes higher than in the standard radiation-dominated case, and is a welcome feature to accomplish a first-order phase transition at the electroweak scale, which is strong enough to facilitate baryogenesis in simple extensions to the standard model Higgs particle. To this end, we will report on the implications of this cosmological model for a first-order phase transition in the minimal standard model, as well as in the standard model with a low cutoff in which the Higgs potential is augmented by a phi^6-operator.

Speaker: Tanja Rindler-Daller (Dept.of Physics, University of Michigan)

TRD_DPF15.pdf

227 Cosmological tests of ultra-light axions

Ultra-light axions (ULAs) with masses in the range 10^{-33} eV <m <10^{-20} eV are motivated by string theory and might contribute to either the dark-matter or dark-energy density of the Universe. We explore the impact of such axions on cosmological observables, like the CMB and galaxy correlation power spectra. We will discuss our use of precision cosmological data (from the Planck satellite and WiggleZ galaxy survey) to test the ultra-light axion hypothesis. After presenting limits to ultra-light axions from cosmological data, we discuss connections between ultra-light axions and primordial gravitational waves from inflation, and highlight the ability of upcoming CMB B-mode searches to provide an independent test of ultra-light axion scenarios.

Speaker: Daniel Grin (University of Chicago)

228 Axion Stars and Bose-Einstein Condensate Dark Matter

The idea that light, self-interacting scalars (e.g. axions) comprise a major component of Dark Matter has recently received renewed interest. It has been shown previously not only that macroscopic bound states of such particles can exist in a Bose-Einstein Condensed phase, but also that this can have unique consequences in astrophysical or terrestrial detection experiments. We present a novel expansion method for integrating the equations of motion for bound states of axion-like particles, which is valid in a wide range of parameter space. This method makes clear the limitations of the procedure widely used in the literature, and also gives a clear physical interpretation of the maximal mass of these axion stars. We briefly discuss some possible astrophysical constraints and detection signatures.

Speaker: Joshua Eby (University of Cincinnati)

Eby_BosonStars_DPF_2015 .pdf

229 Cosmological Non-Constant Problem: Cosmological bounds on TeV-scale physics and beyond

We study the influence of the fluctuations of a Lorentz invariant and conserved vacuum on cosmological metric perturbations, and show that they generically blow up in the IR. We compute this effect using the Kallen-Lehmann spectral representation of stress correlators in generic quantum field theories, as well as the holographic bound on their entanglement entropy, both leading to an IR cut-off that scales as the fifth power of the highest UV scale (in Planck units). One may view this as analogous to the Heisenberg uncertainty principle, which is imposed on the phase space of gravitational theories by the Einstein constraint equations. The leading effect on cosmological observables come from anisotropic vacuum stresses which imply: i) any extension of the standard model of particle physics can only have masses (or resonances) < 24 TeV, and ii) perturbative quantum field theory or quantum gravity become strongly coupled beyond a cut-off scale of Lambda < 1 PeV. Such a low cut-off is independently motivated by the Higgs hierarchy problem. This result, which we dub the cosmological non-constant problem, can be viewed as an extension of the cosmological constant (CC) problem, demonstrating the non-trivial UV-IR coupling and (yet another) limitation of effective field theory in gravity. However, it is more severe than the old CC problem, as vacuum fluctuations cannot be tuned to cancel due to the positivity of spectral densities or entropy. We thus predict that future advances in cosmological observations and collider technology will sandwich from above and below, and eventually discover, new (non-perturbative) physics beyond the Standard Model within the TeV-PeV energy range.

Speaker: Niayesh Afshordi

Afshordi_CnC_APS_AnnArbor_2015.pdf

230 Disorder: From Wires to Particle Production in Cosmology

The early universe is likely filled with a large number of interacting fields with unknown interactions. How can we quantitatively understand particle production (for example, during inflation and reheating after inflation) when such fields undergo a sufficient number of non-adiabatic, non-perturbative interactions ? Based on a precise mapping between particle production in cosmology to resistivity in disordered quasi one-dimensional wires, I provide a powerful statistical framework to resolve such seemingly intractable calculations. A number of phenomenon in disordered wires find an analogue in particle production. For example, Anderson localization in quasi one-dimensional wires can be directly mapped to exponential particle production in the early universe. Evolution equations as well as explicit solutions for the distributions of the number density of particles, along with possible applications will be provided.

Speaker: Mustafa Amin (University of Cambridge)

Amin_WiresToCosmology.pdf

Neutrino Physics

231 Neutrino Flux Studies at NOvA

We present the beam systematics study of the neutrino flux in NOvA. Systematic errors on the flux at the near detector (ND), far detector (FD), and the ratio, FD/ND, due the beam-transport and hadron production are estimated. The data from ND are used to constrain the Muon (from Pion-decay) and Kaon yields relevant for the Nue and Numu Flux. Additional constraint on the Kaon is obtained from the data from the ND-on-the-Surface (NDOS), a prototype NOvA detector.

Speaker: Kuldeep Maan (Panjab University, Chandigarh/Fermilab)

DPF2015_Kuldeep.pdf

232 Neutrino CCQE Cross Section Discrepancies with Data and Generators

Neutrino cross section measurements are important for current and future generation neutrino long baseline experiments, which measure neutrino mixing parameters. Measurements of neutrino cross sections help to constrain and validate neutrino-nucleon interaction models. The current CCQE neutrino cross sections from MiniBooNE and MINERvA along with the T2K data have strong disagreement with the predictions from neutrino generators. This talk looks into possibilities to describe this discrepancy such as the neutrino-nucleon interaction models from Nieves et. al.

Speaker: Andrew Cudd

abcudd_dpf_2015.pdf

233 nuPRISM

See attached PDF.

Speaker: Gregorio Ponti (MSU)

nuPRISM.pdf

234 First Search for EMC Effect and Shadowing in Neutrino Scattering at MIENRvA

MINERvA is a neutrino scattering experiment located at Fermi National Accelerator laboratory in Batavia IL. MINERvA has recently made a measurement of neutrino-nucleus deep inelastic scattering on the nuclei C, Fe, Pb and plastic scintillator. he deep inelastic data contain a measurement of EMC and shadowing nuclear effects in neutrinos. This talk will discuss the DIS measurement and analysis. Comparisons of the data with contemporary neutrino generators and nuclear theories will be presented.

Speaker: Joel Mousseau

mousseau.pdf

235 Electron neutrino charged-current quasi-elastic scattering in the MINERvA experiment

The electron-neutrino charged-current quasi-elastic (CCQE) cross-section on nuclei is an important input parameter to appearance-type neutrino oscillation experiments. Current experiments typically work from the muon neutrino cross-section and apply corrections from theoretical arguments to obtain a prediction for the electron neutrino cross-section, but to date there has been no experimental verification of the estimates for this channel at an energy scale appropriate to such experiments. We present the first measurement of an exclusive reaction in few-GeV electron neutrino interactions, namely, the cross-section for a CCQE-like process, made using the MINERvA detector. The result is given both as differential cross-sections vs. the electron energy, electron angle, and $Q^{2}$, as well as a total cross-section vs. neutrino energy.

Speaker: Jeremy Wolcott (University of Rochester)

2015-08-06 Wolcott nu_e CCQE - DPF.pdf

236 Coherent Charged Pion Production at MINERvA

Neutrino-induced coherent charged pion production on nuclei is a rare, inelastic interaction that produces a charged lepton and pion in the forward direction while leaving the nucleus intact. Understanding this process at few GeV neutrino energy is important for precision measurements of neutrino oscillation parameters. MINERvA has measured muon neutrino and antineutrino coherent charged pion production on carbon from neutrino energies of 1.5 to 20 GeV. The measured kinematics disagree significantly with the predictions of the model employed by current oscillation experiments.

Speaker: Aaron Mislivec (University of Rochester)

MislivecDPF2015.pdf

EWK and Higgs Sector: New Higgs Production

Convener: Christopher Carl Neu (Department of Physics-University of Virginia-Unknown)

237 Usefulness of effective field theory in Higgs plus jet production

The Higgs+jet channel at the LHC is sensitive to the effects of new physics both in the total rate and in the transverse momentum distribution at high pT. We examine the production process using an effective field theory (EFT) language and discuss the possibility of determining the nature of the underlying high-scale physics from boosted Higgs production. The effects of heavy color triplet scalars and top partner fermions with TeV scale masses are considered as examples and Higgs-gluon couplings of dimension five and dimension seven are included in the EFT.

Speaker: Ian Lewis (SLAC)

IL_DPF_2015.pdf

238 New Physics in Double Higgs Production

Double Higgs production is a unique collider process, enabling the determination of the Higgs self-coupling, but is exceedingly rare in the Standard Model. I will review recent developments in the phenomenology of Higgs pair production. The double Higgs cross section may be enhanced not only by a modified Higgs self-coupling, but also by anomalous couplings involving the quarks and the Higgs, resonant enhancements, exotic decays, and new particles contributing to the loop amplitudes. Discerning between these possibilities will be central to future experimental studies, and I will discuss theoretical progress that can help guide such an investigation.

Speaker: Ahmed Ismail (Argonne National Laboratory/University of Illinois at Chicago)

dpf_ai.pdf

239 Search for associated production of a Higgs boson with a single top quark

We present a search for the production of a Higgs boson in association with a single top quark (tHq), using data samples collected by the CMS detector in pp collisions at center-of-mass energy of 8 TeV corresponding to integrated luminosity of 19.7 fb$^{−1}$. The search exploits a variety of top quark and Higgs boson decay modes resulting in final states with photons, bottom quarks, or multileptons, and employs a variety of machine learning techniques to maximize the sensitivity to the signal. The present analysis is optimized for a scenario where the Yukawa coupling has sign opposite to the standard model prediction, which would result in a large enhancement of the signal cross section. Results for individual final states and a combined result will be presented.

Speaker: Kenneth Bloom (University of Nebraska (US))

thq_dpf_150806.pdf

240 Searches for associated top quark and Higgs boson production at the ATLAS experiment

The production of Higgs bosons in association with top quark pairs ($t\bar tH$) provides a measurement of the top quark Yukawa coupling that can be used to constrain possible deviations from the Standard Model induced by new physics. This talk will cover the results of the searches for $t\bar tH$ production at the ATLAS experiment using data collected during LHC Run 1. These include analyses targeting the $H \to b\bar b$, $H \to WW$, $H \to \tau \tau$, and $H \to \gamma \gamma$ decays.

Speaker: Peter Onyisi (University of Texas (US))

20150806_dpf.pdf

Quark and Lepton Flavor Physics

241 Control penguin effect in Bs->JpsiPhi at LHCb

Speaker: Liming Zhang (Tsinghua University (CHINA))

Penguin-DPF.pdf

242 A Selection of Three ATLAS B-Physics Results: A Search Beyond the Standard Model, A Precision Measurement, and the Discovery of a New Heavy Meson

Speaker: Aaron Taylor (University of New Mexico (US))

aaron_DPF_2015.pdf

243 Observation of B+→ψ(2S)K+

Speaker: Reddy Pratap Gandrajula

244 Observation of CP violation in B0->DC P (∗)h0 decays in a combined analysis using BABAR and Belle data

Speaker: Soeren Andre Prell (Iowa State University (US))

Prell-DPF2015.pdf

BSM Physics

245 Recent CMS searches for exotic phenomena beyond the Standard Model

Many scenarios of physics beyond the Standard Model predict exotic phenomena, such as leptoquarks, magnetic monopoles, extra dimensions, and heavy neutrinos. Such phenomena may be identified by various signatures, including a momentum imbalance in the event; a decay displaced from the interaction point; or a resonance of leptons, jets, or photons. This talk presents the results of recent exotics searches by the CMS experiment at the LHC.

Speaker: Wells Wulsin (Ohio State University (US))

20150806_EXORecentResults.pdf

246 Prospects for a Search for Vector-Like Quarks with Events that have Two Leptons of the Same Charge + b-Jets at $\sqrt{s}$ = 13 TeV at ATLAS

Vector-like quarks are predicted in several beyond the Standard Model theories. In some models, there is strong coupling to third generation quarks and the vector-like heavy quarks, T and B, can decay into several different channels involving third generation quarks. We search for vector-like quarks using events that have two leptons of the same charge and $\ge$ 1 b-jet. The prospects for discovery of vector-like quarks using pp collisions from the LHC Run II data collected with the ATLAS detector are presented. The method for determining the largest instrumental background, fake or non-prompt leptons, using data is discussed. The discovery reach for vector-like quarks at $\sqrt{s}$ = 13 TeV is compared against published results from Run 1 at 8 TeV.

Speaker: Sarah Louise Jones (University of Arizona (US))

jones_DPF_SSbjets_20150806.pdf

247 Searches for Vector-Like Quarks at CMS

Vector-Like Quarks (VLQs) appear in many models of new physics. Unlike SM chiral quarks, which only have left-handed charged currents, VLQs have both right and left-handed charged currents while still transforming the same way under SM gauge groups. Searches were performed during the LHC Run I for the VLQ partners of the top and bottom quarks, the T’ and B’. The T’ and B’ are pair-produced and decay to tH and bH, respectively. No VLQs were observed during Run I. The most recent limits for these channels will be presented. A first look at searches for singly and pair produced VLQs in the LHC Run II will also be shown.

Speaker: Robert Stringer (University of Kansas (US))

VLQ-DPF2015v3.pdf

248 Model-Independent Production of a Top-Philic Resonance at the LHC

We investigate the collider phenomenology of a color-singlet vector resonance, which couples to the heaviest quarks, the top quarks, but very weakly to the rest of the fermions in the Standard Model. We find that the dominant production of such a resonance does not appear at the tree level -- it rather occurs at the one-loop level in association with an extra jet. Signatures like t anti-t plus jets readily emerge as a result of the subsequent decay of the resonance into a pair of top quarks. Without the additional jet, the resonance can still be produced off-shell, which gives a sizeable contribution at low masses. The lower top quark multiplicity of the loop induced resonance production facilitates its reconstruction as compared to the tree level production that gives rise to more exotic signatures involving three or even four top quarks in the final state. For all these cases, we discuss the constraints on the resonance production stemming from recent experimental measurements in the top quark sector. We find that the top-philic vector resonance remains largely unconstrained for the majority of the parameter space, although this will be scrutinized closely in the Run 2 phase of the LHC.

Speaker: K.C. Kong (University of Kansas)

K.C.Kong-DPF2015.pdf

249 Searches for Micro Black Holes and String Balls with the ATLAS Detector During Run 1

Models postulating extra spatial dimensions, in which only the gravitational field propagates, address the long-standing hierarchy between the electroweak scale and the gravitational (Planck) scale. Most of these models allow the production of non-perturbative gravitational states, such as micro black holes and string balls, at Large Hadron Collider collision energies. Searches for such states are presented in a variety of final states that include high transverse momentum jets and/or leptons, using 20.3 fb$^{-1}$ of proton-proton collision data recorded by the ATLAS detector at $\sqrt{s}$=8 TeV. No excess of events beyond Standard Model expectations is observed in any of the channels and upper limits on the visible cross-sections for non-Standard Model production are set for final states with large scalar sum of jet and lepton transverse momenta. Using a wide variety of models for black hole and string ball production and decay, exclusion contours are determined as a function of the production mass threshold and the fundamental gravitational scale.

Speaker: Nathan Rogers Bernard (University of Massachusetts (US))

nbernard_DPF2015.pdf

250 Search for disappearing tracks

We present a search for long-lived charged particles that decay within the CMS detector and produce the signature of a disappearing track. Disappearing tracks are identified as those with little or no associated calorimeter energy deposits and with missing hits in the outer layers of the tracker. The search uses proton-proton collision data recorded at sqrt(s) = 8TeV that corresponds to an integrated luminosity of 19.5 /fb. The results of the search are interpreted in the context of the anomaly-mediated supersymmetry breaking model and in terms of the phenomenological MSSM.

Speaker: Wells Wulsin (Ohio State University (US))

20150806_DPFDisappTrks.pdf

251 Search for Monotop Production in Semi-Leptonic Decays of Top Quarks at $\mathbf{\sqrt{s}= 8}$ TeV Using the ATLAS Detector

This beyond the Standard Model search looks for events where single top quarks are produced in association with missing transverse energy. This missing transverse energy can be attributed to a neutral, long lived or stable, non-interacting particle which could be considered a dark matter candidate. The final state topology can either be created via baryon number violating or flavor changing neutral current interactions. Data collected with the ATLAS detector at a center-of-mass energy of 8 TeV during 2012 corresponding to an integrated luminosity of $20.3$ fb$^{-1}$ are used. The current search results will be presented along with future plans for the analysis.

Speaker: Andrew Mc Rae Chegwidden (Michigan State University (US))

Chegwidden_DPF2015.pdf

252 Constructing an Inclusive Lepton Early Warning System

Many beyond the Standard Model Physics scenarios searched for at the LHC predict the existence of new force mediating Gauge Bosons, often termed resonances, such as the Z' and W' Traditionally searches for resonances have relied on the Invariant Mass and Transverse Mass as the discriminating search variables; however, the inclusive lepton pT spectrum offers a unique way to search for both resonances simultaneously in a model independent way, since the signature of a two body decay would appear as a Jacobian Peak over a smooth falling Standard Model background. We describe a system based on this idea, fully tested with 8 TeV Run-I data at various integrated luminosities, and discuss its possible use as an unbiased "early warning system" for future data-taking.

Speaker: Christopher Willis (Michigan State University (US))

willis_DPF2015.pdf

253 The Most Important Searches Missing From Run I

I will discuss several important gaps in LHC coverage for signatures of new physics beyond the standard model. While many of these signatures involve exotic objects, others with be composed entirely of prompt standard detector objects. Special focus will be given for signatures that emerge generically in broad classes of models. This talk will cover both opportunities for existing coverage to be improved, and entirely new search strategies with the potential to make discoveries even within 8 TeV data.

Speaker: Jared Evans

MostImportantSearches.pdf

Accelerators, Detectors, Computing

254 FELIX: the detector readout upgrade of the ATLAS experiment

After the Phase-I upgrade and onward, the Front-End Link eXchange(FELIX) system will be the interface between the readout system and the detector front-end electronics and trigger electronics at the ATLAS experiment. FELIX will function as a gateway to a commodity switched network which will use standard technologies (Ethernet or Infiniband) to communicate with data collecting and processing components. In this talk the system architecture of FELIX will be described and the testing results of the FELIX demonstrator will be presented.

Speaker: Soo Ryu (Argonne National Laboratory (US))

dpf2015_felix.pdf

255 Design Study of the Options for the ATLAS Muon Drift Tube (MDT) Electronics for Phase-II

To reduce the Level-1 muon trigger rate and sharpen the trigger threshold, the ATLAS Muon Drift Tube (MDT) detector will be used at Level-1 after the Phase-II upgrade. The increase of incoming data rate and the long readout time of MDT impose great challenges for the design of the readout electronics. We propose to transmit both low precision trigger data and high precision readout data together. A Verilog simulation of the data capture, multiplexing, and serialization, and transmission of all data completely off detector will be shown. In addition, the distribution of latencies from the crossing to the transmission along the output fiber will be exhibited to confirm that all data will be in place prior to the trigger generation.

Speaker: Jay Chapman (High Energy Physics)

SendAllofMDTMuDPF.pdf

SendAllofMDTMuDPF.pptx

256 Characterization of the Trigger Data Serializer ASIC Prototype for the ATLAS Forward Muon Detector Upgrade

The small-strip Thin-Gap Chambers (sTGC) will be used as both trigger and precision tracking detectors for the Phase-I upgrade of the ATLAS New Small Wheel (NSW) muon detector. A Trigger Data Serializer (TDS) ASIC is needed on the frontend board to transmit trigger data to other circuits located on the rim of the NSW detector. The large number of input channels, short time available to prepare and transmit trigger data, high speed output data rate, harsh radiation environment, and low power consumption all impose great challenges on the design of this ASIC. We present our design of the TDS ASIC and the characterization of its performance from tests of the prototype we built.

Speakers: Mr Liang Guan (University of Michigan), Liang Guan

ATLAS_NSW_TDS_Liang_DPF2015_fin.pdf

257 Design and Test of a Signal Packet Router Board Prototype for the ATLAS Forward Muon Detector Upgrade

The present small wheel detector at ATLAS will be replaced with a New Small Wheel (NSW) detector to handle the increase in data rates and harsh radiation environment expected at the LHC. This NSW detector will contain eight layers of small-strip thin-gap chambers, which will be used for both muon trigger and precision tracking. A signal packet Router board is needed to handle all trigger data and serves as a very fast switching-yard between incoming active TDS signals and a limited number of optoelectronic outputs. The components of a router prototype have been tested in a radiation environment to meet ATLAS radiation tolerance criteria. We will present the design and the test result of the router prototype.

Speaker: Ms Xueye Hu (University of Michigan)

4_DPF_2015_router_0806_v1.pdf

258 Real Time Tracker Based Upon Local Hit Correlation Circuit for Silicon Strip Sensors

ATLAS is a general purpose experiment at the LHC at CERN. For the planned high luminosity upgrade of the LHC, a significant performance improvement of the ATLAS detector is required, including a new tracker and a new trigger system that makes use of charged track information early on. The current ATLAS baseline is to seed the lowest trigger level with calorimeter and muon information only, but exploration of real time track correlation as will be presented in this talk is nevertheless of interest, as the upgraded trigger design has not yet been finalized. For this, a new readout scheme in parallel with conventional readout, called the Fast Cluster Finder (FCF), was included in the latest prototype of the ATLAS strip detector readout chip, the ABC130. The FCF is capable of finding hits within 6 ns and transmitting the found hit information synchronously every 25 ns. Using the FCF together with external correlation logic makes it possible to look for pairs of hits consistent with tracks from the interaction point above a transverse momentum threshold. A correlator logic finds correlations between two closely spaced parallel sensors, a "doublet", and can generate information used as input to a lowest level trigger decision. Such a correlator logic was developed as part of a demonstrator and was successfully tested in an electron beam. The results of this test beam experiment proved the concept of the real time track vector processor with FCF.

Speaker: Niklaus Lehmann (Lawrence Berkeley National Lab. (US))

NiklausLehmann_DPF2015.pdf

259 Impact of the GEM-based Upgrade of the CMS Forward Muon System on Trigger Performance

A large increase in the instantaneous luminosity of the upgraded LHC complex has the potential of significantly degrading the performance of the CMS Level-1 muon trigger in the forward region. Deployment of a new GE1/1 detector system based on the novel GEM technology and its integration with the existing CSC chambers allows to alleviate these concerns. The exceptionally high rate of incident particles in the very forward region makes GEM an excellent technology choice to ensure high muon hit reconstruction efficiency. We will show that integration of the information from the new GE1/1 and existing CSC chambers in station ME1/1 at the level of online electronics allows for a vastly improved muon momentum resolution of the Level-1 trigger. With the upgrade, the CMS muon trigger in the very forward region will see an order of magnitude decrease in the trigger rate and an increase in trigger efficiency allowing CMS to maintain low muon $p_T$ thresholds. The latter is critical for many searches and measurements, both in the Higgs domain as well as in scenarios with hidden sectors, SUSY in compressed scenarios etc. Similar upgrade of CMS with GE2/1 system will reinforce physics performance gains in the high-luminosity LHC operations. The importance of the GEMs upgrade will be high even in the highest luminosity operating regime when the CMS deploys a tracking trigger system, as standalone muon trigger will maintain CMS sensitivity to new physics scenarios predicting existence of new long-lived particles decaying away from the interaction point.

Speaker: Tao Huang (Texas A & M University (US))

GEMCSC_DPF_0806_finaldraft.pdf

260 A Level-1 Track Trigger for the CMS Phase 2 Upgrade

The long-term objectives for the Large Hadron Collider (LHC) include data sets with integrated luminosity of several thousand inverse femtobarns. To achieve these, the LHC will run with high intensity beams, which will cause multiple interactions per beam crossing. The number of multiple interactions will be in the range of 140-200. Triggering under these conditions is very challenging and will require new capabilities at the first trigger stage. One possible improvement is the ability to perform charge particle reconstruction in the silicon tracking system. This presentation will review the benefits of including tracking at the first level of the CMS trigger and will discuss the possibility of using pattern recognition algorithms implemented in commercially available FPGAs. The results of initial algorithm performance and a hardware model for a demonstrator system will be presented.

Speaker: Brian Lee Winer (Ohio State University (US))

DPF15_L1Tracking_Final.pdf

261 The sPHENIX Calorimeter Readout Electronics

A new detector, sPHENIX, is being proposed to explore the quark-gluon plasma through the measurement of jet properties in heavy ion collisions at the Relativistic Heavy Ion Collider, RHIC, at Brookhaven National Laboratory. The detector is based on the 1.5T super conducting solenoid magnet formally used for the BaBar experiment and consists of charged particle tracking, electromagnetic and hadronic calorimetry with a high speed data acquisition system capable of recording data at rates up to 15 KHz. The Calorimeters will use a common readout design based on silicon photomultipliers (SiPMs) that are immune to magnetic fields for the optical readout. In this talk we will discuss the choice of technologies, global design, and the technical challenges of the calorimeter readout.

Speaker: Eric Mannel (Brookhaven National Labs)

EJM_DPF-2015.pdf

EJM_DPF-2015.pdf

QCD and Heavy Ions

Convener: Aaron Angerami (Columbia University (US))

QCDTevDPF2015.pdf

262 Extraction of the proton radius from electron-proton scattering data

We perform a new analysis of electron-proton scattering data to determine the proton electric and magnetic radii, enforcing model-independent QCD-based constraints of form factor analyticity. A wide-ranging study of possible systematic effects is performed. An improved analysis is developed that rebins data taken at identical kinematic settings, and avoids a scaling assumption of systematic errors with statistical errors. Employing standard models for radiative corrections, our improved analysis of 2010 Mainz A1 collaboration data yields a proton electric radius rE=0.895(20) fm and magnetic radius rM=0.777(38) fm. A similar analysis applied to world data (excluding Mainz data) implies rE=0.918(24) fm and rM=0.913(37) fm. The Mainz and world values of the charge radius are consistent, and a simple combination yields a value rE=0.904(15) fm that is 4σ larger than the CREMA muonic hydrogen determination. The Mainz and world values of the magnetic radius differ by 2.5σ, and a simple average yields rM=0.847(27) fm. The circumstances under which published muonic hydrogen and electron scattering data could be reconciled are discussed, including a possible deficiency in the standard radiative correction model which requires further analysis.

Speaker: Richard Hill

hill_DPF_proton.pdf

263 Parton Dynamics at PHENIX

Investigating partonic interactions is one of the primary goals of the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC). RHIC is specially tailored for studying intrinsic partonic spin-momentum correlations due to its unique ability to collide polarized proton beams. Transverse single-spin asymmetries of order 10% have been measured in PHENIX at center of mass energies from 62.4 GeV to 200 GeV, similar to previous measurements. These results indicate that there exist partonic transverse momentum effects within the proton and/or within the process of hadronization. The MPC-EX, a new silicon-tungsten preshower detector at PHENIX, has taken data for the first time this year with the intent of shedding further light on the origins of these asymmetries. A review of the status of the detector and of future planned measurements will be presented. An overview of ongoing work by PHENIX aimed at measuring intrinsic partonic transverse momentum will be discussed.

Speaker: Joseph Osborn (University of Michigan)

DPF_2015_Osborn_Parton_Dynamics.pdf

264 Saturation physics on the energy frontier

For decades, hadron structure research has progressed toward probing the behavior of constituent quarks and gluons (partons) at smaller and smaller fractions $x$ of their parent hadron's momentum. At sufficiently small $x$, this behavior is expected to transition to saturation, a condition where parton self-interactions and multiple scatterings become significant. High-energy proton-ion collisions at RHIC and the LHC provide the best available testing ground for the saturation model. However, producing precise numerical predictions from the model is a complicated task; the state of the art in this area involves next-to-leading order QCD calculations, which are difficult to do numerically. In this talk I'll review recent progress in extracting numerical predictions from saturation models and matching them to experimental results.

Speaker: David Zaslavsky (Central China Normal University)

dpf2015-zaslavsky.pdf

265 The sPHENIX Experiment

sPHENIX is a proposal for a new experiment at RHIC capable of measuring jets, jet correlations and upsilons to determine the temperature dependence of transport coefficients of the quark-gluon plasma (QGP). The sPHENIX detector will acquire a large sample of events with a high rate data acquisition system from a large acceptance spectrometer with full hadronic and electromagnetic calorimetry and precision tracking. A program of systematic measurements near the QGP transition temperature at RHIC will complement existing and planned measurements being made as part of the LHC heavy-ion program. The talk will describe the proposed new detector and some of the key measurements enabled by it.

Speaker: John Haggerty (Brookhaven National Laboratory)

sphenix_haggerty_dpf2015_3.pptx

266 The LPM Effect in Sequential Bremsstrahlung

Energy loss of very high energy particles traversing a medium is dominated by the splitting processes of hard bremsstrahlung and pair production. These splitting processes are coherent over large distances, leading to a suppression known as the Landau-Pomeranchuk-Migdal (LPM) effect, relevant to both jet energy loss in quark-gluon plasmas and the evolution of cosmic ray showers. In the QCD case, there is a potentially important correction to the usual treatment of the LPM effect, arising from cases where the coherence lengths of two consecutive splitting processes overlap. I will (i) outline the physics behind the method for calculating the LPM effect and these corrections, and (ii) briefly summarize the types of results available so far.

Speaker: Peter Arnold (University of Virginia)

arnold.pdf

267 Open heavy flavor measurements in heavy ion collisions with CMS

The study of heavy quark production is an effective way of investigating the properties of the medium created in heavy ion collisions. Heavy quarks are sensitive to the transport properties of the medium since they are produced at the early stages of collision. Heavy quarks can also reveal critical features of the medium because they interact with the medium differently from light quarks. Studies of open heavy flavor production in both PbPb and pPb collisions can help us understand the flavor dependence of energy loss in the medium. In this talk we present recent open heavy flavor results and perspectives of future studies with CMS.

Speaker: Jian Sun (Purdue University (US))

2015DPF_jiansun_v3.pdf

20:00 Guest Lecture: Janna Levin

Friday 7 August

07:30 Breakfast

Session I-D

Convener: Kate Scholberg (Duke University)

268 Exploring Neutrinos Via Oscillations in the Atmosphere, at Reactors, and at Accelerators

The discovery of neutrino mass in 1998 spawned a world-wide effort to better understand neutrino properties using neutrinos from the Sun, the atmosphere, reactors, and from accelerators. This program of study has taught us much about neutrinos, but many important questions remain: What is the ordering of neutrino masses? What are the symmetries in neutrino mixing? Do neutrinos violate CP? Is there more to be learned beyond the now-standard picture of neutrino oscillations? Precise measurements at the world’s reactors coupled with ambitious long-baseline experiments at accelerators are playing a unique role in answering these questions. In this talk, I will review the current experimental situation with a particular emphasis on the most recent experimental results.

Speaker: Mark Messier (Indiana University)

DPF2015-Messier.pdf

269 Neutrinos and Beyond the Standard Model Physics

There has been tremendous progress in understanding the neutrino properties since the discovery of neutrino masses by SuperKamiokande in 1998. The experimental data presents the following theoretical challenges: why the neutrino masses are so small compared to charged fermion masses, and why the leptonic mixing pattern is so different from their quark counterpart. I will review some recent ideas that are aiming at answering these questions and their phenomenological implications. I will also elucidate how these ideas may allow us to answer some other fundamental questions in physics.

Speaker: Prof. Mu-Chun Chen (University of California - Irvine)

2015DPF_nu_MCChen.pdf

270 Weighing Neutrinos

Neutrino oscillation experiments performed throughout the latter half of the twentieth century have yielded valuable information on the nature of neutrino masses and mixings. The evidence gathered has provided the first positive evidence for physics beyond the standard model. Currently, a new suite of precision experiments will come online to provide greater insight into the physics and significance of neutrino mass. This talk will review our current state of knowledge on neutrino masses, and how new experiments --such as beta decay and neutrinoless double beta decay measurements— will complement that knowledge in years to come.

Speaker: Joseph Formaggio (MIT)

Formaggio_Friday_NeutrinoMasses.key

Formaggio_Friday_NeutrinoMasses.pdf

10:15 Cafe Break

Session II-D

Convener: JoAnne Hewett (SLAC)

271 Breaking the Myth of the "Non-Traditional" Physicist: The Real Story About Employment for Physics Graduates

Physics degree holders are among the most employable in the world, often doing everything from managing a research lab at a multi-million dollar corporation, to developing solutions to global problems in their own small startups. Science and Technology employers know that with a physics training, a potential hire has acquired a broad problem-solving skill set that translates to almost any environment, as well as an ability to be self-guided and -motivated so that they can teach themselves whatever is needed to be successful at achieving their goals. Therefore it's no surprise that the majority of physics graduates find employment in private--sector, industrial settings. At the same time, only about 25% of graduating PhDs will take a permanent faculty position--yet academic careers are usually the only track to which students are exposed while earning their degrees. In this talk, I will explore less-familiar (but more common!) career paths for physics graduates, and will provide information on resources to boost your career planning and job hunting skills.

Speaker: Prof. Crystal Bailey (American Physical Society)

Career Talk.pdf

Career Talk.pptx

272 The Highest Energy Frontier

The study of cosmic rays beyond 10^18 eV gives us glimpses into the most energetic phenomena in the universe since the Big Bang. Projects such as the Pierre Auger Observatory, the HiRes Experiment and the Telescope Array have demonstrated the extragalactic origin of the most energetic particles. They have mapped out particle arrival directions on the sky to look for evidence of sources, have searched for neutrino, photon and neutron candidates at the highest energies, have measured proton interaction cross sections beyond the reach of the LHC. They have studied the mass composition of the highest energy particles, have investigated the effects of magnetic fields on the propagation of particles across cosmological distances, are busy untangling the transition between Galactic and extragalactic sources, and are joining the worldwide chorus of multimessenger studies to seek violent but distant transient events in the cosmos. Meanwhile new techniques are being devised for increased sensitivity in the realm of lowest particle fluxes. We will review the latest results and prospects at the highest energy frontier.

Speaker: Stephane Coutu (Penn State University)

Coutu_2015_DPF_posted.pdf

273 Black Holes in String Theory

Black holes are central to the study of string theory. First, we must understand how string theory solves the information puzzle found by Hawking; this direction explores the fundamental structure of spacetime. Second, one finds an intriguing extension of the idea that surface area measures entropy -- the Ryu-Takayanagi relation between surface area and entanglement entropy. Lastly, the AdS/CFT duality map relates the gravitational dynamics of black holes to the thermodynamical behavior of condensed matter systems. I will briefly summarize some of the progress in these directions over the past few years.

Speakers: Samir Mathur (Ohio State University), Samir Mathur

DPF15brief.pdf

Careers in Physics Forum: (box lunch provided)

DPFCareerPanelSpeakerBios.pdf

12:30 Lunch (box lunch provided)

Education and Outreach

Conveners: Don Lincoln (Fermi National Accelerator Lab. (US)), Nicole Michelotti (University of Michigan)

274 How to be a successful freelance science reporter

Thanks to social media and blogging platforms, it’s never been easier for anyone to be a science news reporter. But finding an audience is tougher. In this talk I will explore how the science stories you choose to write about, and the way you choose to write about them, can improve your chances of being noticed - potentially even by a professional popular science editor who is willing to offer a penny (and usually considerably more) for your thoughts. Colin Barras has been a professional science writer and editor for eight years, working at New Scientist magazine in London, CERN, and most recently on a freelance basis.

Speaker: Colin Barras (freelance writer)

Barras-sciencewriting.pdf

Barras-sciencewriting.pptx

275 Enhancing Scientific Outreach with Social Media

Social media is a very powerful tool that can give us access to a wide audience across the globe at nearly the speed of light. The focus of this talk will be on different ways in which we can use social media to engage people of all ages and educational backgrounds in topics of science. By making complicated physical concepts easier to understand, you can expand your reach, your reader's understanding of reality and our place in it.

Speakers: April Jakubowski, Sophia Nasr

276 HEP User Community Government Outreach

High Energy Physics research in the U.S. is funded almost entirely by the federal government. Our field competes for federal dollars with colleagues as close as Nuclear Physics, and as far removed as the National Park Service or School Lunch Program. How does our budget get put together, and by whom? What do we do, specifically as a User community, to advocate for our research program to the people making the funding decisions for our field? Finally, learn how you can help by getting directly involved with government outreach. Dr. Breese Quinn, Assoc. Prof. at the University of Mississippi and member of the D0 and Muon g-2 collaborations, has worked in government outreach for more than a decade, including several years leading HEP Congressional visits as Chair of Fermilab’s UEC Government Relations.

Speaker: Breese Quinn (University of Mississippi)

Quinn_DPF_080715.pdf

277 ATLAS virtual visits

ATLAS and CMS Virtual Visits is a project initiated in 2011 for the Education and Outreach program of the two big LHC experiments at CERN. Its goal is to promote public appreciation of the LHC physics program and HEP, in general, through direct dialogue between ATLAS physicists and remote audiences. A Virtual Visit is an IP-based videoconference, coupled with a public webcast and video recording, between physicists at the ATLAS or CMS Experiment at CERN, and remote locations around the world that typically include high school or university classrooms, Masterclasses, science fairs, or other special events, usually hosted by collaboration members. Over the past two years, more than 10,000 people, from all of the world’s continents, have actively participated in ATLAS and CMS Virtual Visits, with many more enjoying the experience from the publicly available webcasts and recordings.  We present an overview of our experience and discuss potential development for the future.

Speaker: Ilija Vukotic (University of Chicago)

ATLAS_CMS_VV_DPF.pdf

ATLAS_CMS_VV_DPF.pptx

Field and String Theory

Conveners: Christopher Herzog (Stony Brook University), David Berenstein (University of California at Santa Barbara)

278 Geometric constraints on the space of $\mathcal{N}=2$ SCFTs

We present a classification of 4d rank 1 $\mathcal{N}=2$ SCFTs, based on a geometrical analysis of the Coulomb Branches of these theories, i.e., their moduli space of vacua. Supersymmetry and the residual $U(1)$ gauge symmetry on the Coulomb Branch allow us to determine some constraints on the geometries that can be consistently interpreted as low energy moduli space of a SCFT. We can have distinct SCFTs corresponding to the same scale invariant geometry but which differ by the set of relevant deformations that are turned on. These in fact correspond to different theories, each with its own flavor structure and matter content transforming in appropriate representations of the flavor group. We classify all the possible deformations of scale invariant Coulomb Branches that satisfy all the low energy consistency conditions and thus can have a consistent interpretation as moduli space of a SCFT. This can be used in conjuction with other approaches, such as S-duality and the conformal bootstrap to obtain a better global understanding of $\mathcal{N}=2$ SCFTs.

Speaker: Mr Matteo Lotito (University of Cincinnati)

LotitoDPF.pdf

279 Gauged linear sigma models on the Omega-deformed two-sphere

I will discuss a new exact formula for supersymmetric correlation functions of gauged linear sigma models (GLSM) with $\mathcal{N}=(2,2)$ supersymmetry on the two-sphere with a twist. More precisely, the $S^2$ supersymmetric background is an ``Omega-background'' which generalizes the familiar A-twist. The formula simplifies previous results and leads to new results for non-Abelian gauge theories. It provides an interesting new tool to study strongly coupled 2d supersymmetric gauge theories with matter. (Based on 1504.06308 with S. Cremonesi and D. S. Park.)

Speaker: Cyril Closset

DPF_March_07_2015.pdf

original paper

280 Magnetic Catalysis in Graphene

One of the most important developments in condensed matter physics in recent years has been the discovery and characterization of graphene. A two-dimensional layer of Carbon arranged in a hexagonal lattice, graphene exhibits many interesting electronic properties, most notably the property that the low energy excitations can be described by the Dirac equation for a massless fermion. These excitations interact strongly via the Coulomb interaction and thus non-perturbative methods can be useful. Using methods borrowed from lattice QCD, we study the graphene effective theory in the presence of an external magnetic field. Graphene, along with other $(2+1)$-dimensional field theories, has been predicted to undergo spontaneous breaking of chiral symmetry including the formation of a gap as a result of the external magnetic field. This phenomenon is known as magnetic catalysis. Our study investigates magnetic catalysis using a fully non-perturbative approach.

Speaker: christopher Winterowd (University of Utah)

DPF_2015.pdf

281 Phenomenology of fundamental spinons

In condensed matter physics, the theory of spin–charge separation dates back to the 1950 paper of Tomonaga [1], but experimental confirmation required almost a half century [2-4]. Here we consider the possibility of a similar phenomenon — inspired in part by the reality of Higgs bosons [5,6] and therefore of at least one Higgs condensate — which would potentially be observable in Run 2 of the LHC. The qualitative phenomenology is simple: These fundamental spinons would carry only angular momentum (as spin 1/2 particles) plus energy and momentum, with no charge of any kind, so they must be detected as e.g. missing transverse momentum. They could be produced in virtual processes, such as the decay of virtual Z bosons, or real processes, such as emission from W bosons, but always involving vector bosons in the presence of a Higgs condensate. Their masses are undetermined by the theory (just as was the mass of the observed Higgs), but the mass of a spinon pair must exceed the mass of a Z boson, since the decay of real Z bosons is completely explained by Standard Model particles. Here we will make no attempt to justify the theory from which the prediction of these spinons emerges [7] (which has many compelling features but requires the introduction of a very large number of novel ideas). The important fact is that the theory does lead to this prediction of new particles which are in principle observable in the foreseeable future, as well as various other predictions — since it cannot even be formulated without supersymmetry, SO(N) grand unification, or vanishing of the usual cosmological constant, and since the simplest version of the theory leads to a self-coupling of the Higgs field whose unrenormalized value is nearly zero. Since the spinons proposed here are closely related to the Higgs, it may be worthwhile to establish historical context: After the electron was discovered in 1897, and the photon was introduced by Einstein in 1905, the richness of behavior associated with spin 1/2 fermions and spin 1 gauge bosons emerged slowly during the following decades. More than a century later, the third kind of Standard Model particle, with spin 0, has finally been discovered, and one should not be completely surprised if some of its implications are yet to be determined. [1] S. Tomonaga, “Remarks on Bloch's method of sound waves applied to many-fermion problems”, Prog. Theor. Phys. 5, 544 (1950). [2] C. Kim, A. Y. Matsuura, Z.-X. Shen, N. Motoyama, H. Eisaki, S. Uchida, T. Tohyama, and S. Maekawa, “Observation of Spin-Charge Separation in One-Dimensional SrCuO2”, Phys. Rev. Lett. 77 4054 (1996). [3] B.J. Kim, H. Koh, E. Rotenberg, S.-J. Oh, H. Eisaki, N. Motoyama, S. Uchida, T. Tohyama, S. Maekawa, Z.-X. Shen, and C. Kim, "Distinct spinon and holon dispersions in photoemission spectral functions from one-dimensional SrCuO2”, Nature Physics 2, 397 (2006). [4] Y. Jompol, C. J. B. Ford, J. P. Griffiths, I. Farrer, G. A. C. Jones, D. Anderson, D. A. Ritchie, T. W. Silk, A. J. Schofield, “Probing Spin-Charge Separation in a Tomonaga-Luttinger Liquid”, Science 325, 597 (2009). [5] ATLAS Collaboration, “Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC”, Phys. Lett. B716, 1 (2012), arXiv:1207.7214 [hep-ex]. [6] CMS Collaboration, “Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC”, Phys. Lett. B716, 30 (2012), arXiv:1207.7235 [hep-ex]. [7] R. E. Allen, “Predictions of a fundamental statistical picture”, arXiv:1101.0586 [hep-th].

Speaker: Prof. Roland Allen (Texas A&M University)

Allen.pdf

Allen.pptx

AstroParticle, Cosmology, Dark Matter Searches, and CMB

Convener: Michael Schubnell (University of Michigan)

282 TeV Astrophysics with the HAWC Observatory

The High-Altitude Water Cherenkov (HAWC) Observatory was completed and began full operation at the end of March 2015. Located at an elevation of 4100 meters above sea level and declination of 19 degrees north near the Sierra Negra volcano in central Mexico, HAWC is sensitive to 100 GeV - 100 TeV gamma-rays and cosmic-rays with a sensitivity to TeV-scale gamma-ray sources that is an order of magnitude better than previous air shower arrays. HAWC’s wide field-of-view (~2 sr), and continuous up-time (24 hours/day) make it an ideal survey instrument. HAWC is uniquely suited to study extremely high energy cosmic-ray sources, search for regions of extended gamma-ray emission, and to identify transient phenomena. HAWC will play a key role in triggering multi-wavelength and multi-messenger studies of active galaxies, gamma-ray bursts, supernova remnants and pulsar wind nebulae. Observation of TeV photons also provide unique tests for a number of fundamental physics phenomena including dark matter annihilation, primordial black hole evaporation and Lorentz invariance violation. This talk will discuss the science of HAWC, summarize the status of the experiment, and highlight first results from analyses of the data.

Speaker: Kirsten Anne Tollefson (Michigan State University (US))

DPF_Highlights_final.pptx

283 A Deep Observation of Gamma-ray Emission from Cassiopeia A using VERITAS

Supernova remnants (SNRs) have long been considered the leading candidates for the accelerators of cosmic rays within the Galaxy through the process of diffusive shock acceleration. The connection between SNRs and cosmic rays is supported by the detection of high energy (HE; 100 MeV to 100 GeV) and very high energy (VHE; 100 GeV to 100 TeV) gamma rays from young and middle-aged SNRs. However, the interpretation of the gamma-ray observations is not unique. This is because gamma rays can be produced both by electrons through non-thermal Bremsstrahlung and inverse Compton scattering, and by protons through proton-proton collisions and subsequent neutral-pion decay. To disentangle and quantify the contributions of electrons and protons to the gamma-ray flux, it is necessary to measure precisely the spectra and morphology of SNRs over a broad range of gamma-ray energies. Cassiopeia A (Cas A) is one such young SNR (~350 years) which is bright in radio and X-rays. It has been detected as a bright point source in HE gamma rays by Fermi-LAT and in VHE gamma rays by HEGRA, MAGIC and VERITAS. Cas A has been observed with VERITAS for more than 60 hours, tripling the published exposure. The observations span 2007-2013, and half of the data were taken at large zenith angles to boost the effective area above few TeV. We will present the detailed spectral and morphological results from the complete dataset.

Speaker: Mr Augusto Ghiotto (Columbia University, VERITAS Collaboration)

Cas A _ DPF 2015 _ Ghiotto.pdf

284 Searching for Primordial Black Holes with TeV Gamma Ray Detectors

Primordial black holes (PBHs) are gravitationally collapsed objects that may have been created by density fluctuations in the early universe and could have arbitrarily small masses down to the Planck scale. Hawking showed that due to quantum effects, a black hole has a temperature inversely proportional to its mass and will emit all energetically allowed species of fundamental particles thermally. PBHs with initial masses of order 5×10^15 g should be expiring in the present epoch with bursts of high-energy particles, including gamma radiation in the GeV -- TeV energy range. The Milagro high-energy observatory, which operated from 2000 to 2008, is sensitive to the high end of the PBH evaporation gamma-ray spectrum. A search of five years of Milagro data set a local (parsec-scale) upper limit of 3.6×10^4 PBH bursts/year/pc3. We will also report the sensitivity of the High-Altitude Water-Cherenkov (HAWC) observatory to PBH evaporation events. Finally, we investigate the final few seconds of black hole evaporation using Standard Model physics and calculate energy dependent PBH burst time profiles in GeV/TeV range. We calculate PBH burst light curves observable by HAWC and explore search methods and potentially unique observational signatures of PBH bursts.

Speaker: James Thomas Linnemann (Michigan State University (US))

dpf 2015.pdf

285 First Limits on the Dark Matter Cross-Section with the High Altitude Water Cherenkov (HAWC) Observatory

The High Altitude Water Cherenkov (HAWC) gamma-ray observatory is a wide field-of-view observatory sensitive to 100 GeV – 100 TeV gamma-rays and cosmic-rays. The HAWC observatory is also sensitive to diverse astrophysical searches for signatures of annihilating and decaying dark matter. These include gamma-ray emission from extended sources of dark matter such as galaxies and Galaxy clusters, emission from the center of the Milky Way, and from non-luminous dark matter subhalos. With its sensitivity to over 2/3 of the sky, HAWC has the ability to probe a large fraction of the sky for the signals of TeV-mass dark matter. In particular, HAWC should be the most sensitive experiment to signals coming from dark matter with masses greater than 10-100 TeV. We will present the HAWC sensitivity to annihilating and decaying dark matter signals for several likely sources of these signals. We will also present early HAWC limits on the dark matter annihilation cross-section from dwarf spheroidal galaxies, objects which are expected to have few astrophysical sources of gamma-rays but high dark matter content.

Speaker: J. Patrick Harding (Los Alamos National Laboratory)

Harding_DPF_6August2015.pdf

286 Searching for Dark Matter Annihilation into Neutrinos with Super-Kamiokande

This work presents indirect searches for dark matter (DM) as WIMPs (Weakly Interacting Massive Particles) using neutrino data recorded by Super-Kamiokande from 1996 to 2014. The results of the search for WIMP-induced neutrinos from the Sun and the Milky Way are discussed. We looked for an excess of neutrinos from the Sun/Milky Way compared to the expected atmospheric neutrino background. Event samples including both electron and muon neutrinos covering a wide range of neutrino energies (GeV to TeV) were used, with sensitivity to WIMP masses down to tens of GeV. Various WIMP annihilation modes were taken into account in the analyses.

Speakers: Kasia Frankiewicz (National Center for Nuclear Research, Poland), Katarzyna Frankiewicz (National Centre for Nuclear Research)

DPF_Frankiewicz_DM.pdf

Neutrino Physics

Conveners: Daniel Hernandez, Irina Mocioiu (Pennsylvania State University), Lindley Winslow (Massachusetts Institute of Technology), Lisa Kaufman (Indiana University)

287 Results from the OPERA experiment at the CNGS beam

The OPERA experiment at the Gran Sasso underground laboratory has been designed to study the $\nu_\mu \to \nu_\tau$ oscillation in appearance mode in the CNGS neutrino beam. Four $\nu_\tau$ candidate events have been confirmed so far, using a sub-sample of data from the 2008-2012 runs. Given the number of analysed events and the low background, $\nu_\mu \to \nu_\tau$ oscillations have been established with a significance of 4.2 sigma. In the talk we will present results based on an increased sample of scanned emulsion target units (bricks). The $\nu_\tau$ data analysis will be updated and discussed, with emphasis on the background constraints obtained by using dedicated data-driven control samples. The analysis of the present tau neutrino and electron neutrino samples in the framework of the 3+1 sterile model will be presented.

Speaker: Dr Tomohiro Hayakawa (Nagoya University)

DPF2015_opera_hayakawa.pdf

288 Prospects for measuring tau neutrino appearance in DeepCore

Neutrino oscillations, and in particular muon neutrino disappearance, have been verified several times and with increasing precision. However to paint a complete picture of neutrino oscillations it is also essential to measure tau neutrino appearance at a very precise level and evaluate the unitarity of the mixing matrix. Recent improvements in the precision of the DeepCore measurement of muon neutrino disappearance were mainly possible due to improvements in reconstruction algorithms and in the efficiency of event selection. In addition to the improved precision for muon neutrino disappearance, these improvements have also opened the possibility of making a statistically significant measurement of tau appearance around the first oscillation maximum at 25 GeV, using the high statistics neutrino sample available. In this presentation we discuss the current progress towards this measurement using DeepCore.

Speaker: Joao Pedro Athayde Marcondes de Andre (Michigan State University/IceCube)

201508_jpamdandre_dpf.pdf

289 Neutrino Physics Prospects with PINGU

The DeepCore extension of the IceCube Neutrino Observatory has established the feasibility of measuring neutrino oscillation parameters using atmospheric neutrinos at energies of roughly 10-60 GeV traveling through the Earth on a range of baselines. The proposed PINGU upgrade of IceCube would reduce the energy threshold to a few GeV, both improving the precision of these measurements and permitting determination of the ordering of the neutrino mass eigenstates through observation of matter effects. Prospects for these observations with PINGU will be discussed.

Speaker: Tyce DeYoung (Michigan State University)

DeYoung_DPF_PINGU.pdf

290 Numu Disappearance with IceCube/DeepCore

Located at the South Pole Station in Antarctica, the IceCube Neutrino Observatory is the world's largest neutrino telescope. In the clearest part of the ice sits a more densely instrumented section, DeepCore, that is able to measure neutrinos from 10-60 GeV. By using DeepCore neutrino oscillations can be observed via numu disappearance. This talk will go over the latest atmospheric disappearance results from IceCube/DeepCore and possible improvements that could be made to the analysis.

Speaker: Joshua Hignight (Michigan State University)

hignight_DPF_09072015.pdf

291 Nucleon Decay Search in SNO+ Water Phase using a Likelihood Approach

SNO+ is a multipurpose, largescale neutrino experiment located deep underground in Sudbury, Ontario. In its initial water-fill phase, it will be highly sensitive to the so-called invisible modes of nucleon decay, a model-independent description of any channel in which nucleons decay to non-visible daughters, such as n $\rightarrow \nu \nu \nu$. Nucleon disappearance in $^{16}$O can lead to excited states of $^{15}$O or $^{15}$N, which deexcite through gamma emission at modestly high energy, forming our signal. The leading limits on this mode were set in SNO and Kamland. However, SNO suffered from backgrounds due to its D$_2$O that will not be present in SNO+, and the branching ratio for the C nuclide studied in Kamland is unfavorable compared to that for O. The major backgrounds in SNO+ will come from solar and reactor neutrinos, and decays of $^{214}$Bi and $^{208}$Tl. We expect to achieve world-leading sensitivity to these modes after only six months of water phase data taking. We report an improvement in sensitivity over our previous estimates from an improved analysis technique that is based on a likelihood analysis of the energy spectrum.

Speaker: Kevin Labe (University of Chicago)

nucleondecaytalk.pdf

EWK and Higgs Sector: Flavor Violation Decay of Higgs

Convener: Howard Haber (Santa Cruz Institute for Particle Physics (SCIPP))

292 Flavor Violating Heavy Higgs Decays at the LHC

We investigate the prospects for LHC discovery of a heavy Higgs boson ($H^0$ or $A^0$) decaying into a top quark and a charm quark within the general two Higgs doublet model (2HDM). Discovery of such signal will greatly improve our understanding of electroweak symmetry breaking and possible sources of tree level flavor changing neutral currents. Almost all the coupling measurements of the 125 GeV Higgs boson at the LHC favor the decoupling limit or the alignment limit of a 2HDM, in which the gauge boson and diagonal fermion couplings of the light neutral Higgs scalar ($h^0$) approach the Standard Model values. In this limit, flavor violating couplings of $h^0$ are naturally suppressed by a small mixing parameter $\cos(\beta-\alpha) \sim 0$, while the off-diagonal couplings of heavier neutral Higgs scalars are sustained by $\sin(\beta-\alpha) \sim 1$. Promising results are found for the LHC running at 13 or 14 TeV center of mass energy.

Speaker: Baris Altunkaynak (University of Oklahoma)

Baris_Altunkaynak_DPF_2015.pdf

293 Search for LFV decays with Hadronic Taus of the Higgs with 2012 Data (ATLAS)

The full data-set collected by the ATLAS detector in 2012 is analyzed to search for Lepton Flavor Violating (LFV) decays of the 125 GeV Higgs boson in final states of $\tau_{had} + \mu$ and $\tau_{had} + e$. The search is based on data samples of proton-proton collisions at $\sqrt s = $ 8 TeV corresponding to an integrated luminosity of $20.3 fb^{-1}$. A cut-based approach is used, optimized to exploit the topology of LFV events, with signal and control regions defined by event kinematics.

Speaker: Robert Najem Clarke (Lawrence Berkeley National Lab. (US))

DPFTalk-CLARKE.pdf

294 Search for Lepton Flavor Violating Decays of the Higgs Boson (CMS)

We present the first direct search for lepton flavor violating (LFV) decays of the Higgs Boson. LFV decays are permitted in many extensions of the standard model. Indirect constraints strongly limit the decay H to e mu, but allow H to e tau and H to mu tau to 10%. We present results in all three channels using the full run 1 data set collected by the CMS experiment at the LHC.

Speaker: Nathan Marshall Kellams (University of Notre Dame (US))

DPF2015_Kellams.pdf

Quark and Lepton Flavor Physics

Conveners: J Michael Williams (Massachusetts Inst. of Technology (US)), Jure Zupan (University of Cincinnati)

295 Experimental Overview of Lepton Non-universality Results and Prospects

Speaker: Brian Keith Hamilton (University of Maryland (US))

DPF-LeptonUni-v2.pdf

296 LHCb data taking strategy for the upcoming LHC runs

Speakers: Kevin Dungs (Technische Universitaet Dortmund (DE)), Kevin Dungs (Technische Universitaet Dortmund (DE))

talk.pdf

297 Searches for New Physics at the Belle II Experiment

Speaker: Boqun Wang

DPF2015_boqunwg.pdf

BSM Physics

Conveners: Kevin Black (Boston University), Nathaniel Craig (UC Santa Barbara), Rouven Essig

298 Automation of non-SUSY two-loop RGEs with PyR@TE: latest developments

In light of the conspicuous absence of SUSY in the energy range explored by the LHC during run I, non-supersymmetric BSM scenarios are becoming more and more attractive. One key ingredient in exploring such BSM physics are the renormalization group equations (RGEs) that are essential for extrapolating the theory to higher energy scales. Although the 2-loop RGEs for a general quantum field theory have been know for some time, it is only recently that their automation has become available in the form of a Python program called PyR@TE. In this talk, I will present the features of PyR@TE as well as the latest developments of the code. In particular, the new ability to deal with sets of fields that have multiple ways of being contracted into a gauge singlet.

Speaker: Dr Florian Lyonnet (LPSC)

DPF2015-Pyrate.pdf

extra_materials

• BetaFunctionTypeIIandaxion.py
• RGEsOutput.pickle
• RGEsOutput.tex
• SolveRGEs.py
• TypeIItoy.model

299 Long-Lived Superparticles with Hadronic Decays at the LHC

Supersymmetry searches at the LHC are both highly varied and highly constraining, but the vast majority are focused on cases where the final-stage visible decays are prompt. Scenarios featuring superparticles with detector-scale lifetimes have therefore remained a tantalizing possibility for sub-TeV SUSY, since explicit limits are relatively sparse. Nonetheless, the extremely low backgrounds of the few existing searches for collider-stable and displaced new particles facilitates recastings into powerful long-lived superparticle searches, even for models for which those searches are highly non-optimized. In this paper, we assess the status of such models in the context of baryonic R-parity violation, gauge mediation, and mini-split SUSY. We explore a number of common simplified spectra where hadronic decays can be important, employing recasts of LHC searches that utilize different detector systems and final state objects. The LSP/NLSP possibilities considered here include generic colored superparticles such as the gluino and light-flavor squarks, as well as the lighter stop and the quasi-degenerate Higgsino multiplet motivated by naturalness. We find that complementary coverage over large swaths of mass and lifetime is achievable by superimposing limits, particularly from CMS's tracker-based displaced dijet search and heavy stable charged particle searches. Adding in prompt searches, we find many cases where a range of sparticle masses is now excluded from zero lifetime to infinite lifetime with no gaps. In other cases, the displaced searches furnish the only extant limits at any lifetime.

Speaker: Zhen Liu

ZhenLiu_DPF2015_Displaced.pdf

300 Phenomenological implications of the naturally aligned NMSSM

The close to SM-like nature of the observed 125 GeV Higgs leads very naturally to a light extended Higgs sector in the Z3 NMSSM. I will explore the very rich phenomenology of this model and highlight specific search channels of interest for the 14 TeV LHC.

Speaker: Dr Nausheen Shah (University of Michigan)

SHAH_DPF2015-2.pptx

301 Supersymmetry Versus Extra Dimensions at the LHC

Non-minimal universal extra dimensions (nmUED) involve the choice of boundary localized kinetic terms (BLKT) for the 5 dimensional gauge bosons and fermions. We find that with suitable choice of these parameters needed to explain the current Higgs data, the BLK terms removes the approximate degeneracy of the KK mass spectrum, and the pair productions of the level-1 quarks and gluons give rise to hard jets, lepton and large missing energy. Thus the LHC will not be able to distinguish between the supersymmetry and extra dimensions, and the production of the 2nd KK excitation will be the key for such a distinction.

Speaker: Satyanarayan Nandi (Oklahoma State University)

NANDI_DPF_2015.pdf

Accelerators, Detectors, Computing

Conveners: Michael Aaron Kagan (SLAC National Accelerator Laboratory (US)), Toyoko Orimoto (Northeastern University (US))

302 Solid xenon bolometers

Cryogenic liquid xenon detectors have become a popular technology in the search for rare events, such as dark matter interactions and neutrinoless double beta decay. The power of the liquid xenon detector technology is in the combination of the ionization and scintillation signals, resulting in particle discrimination and improved energy resolution over the ionization-only signal. The improved energy resolution results from a unique anti-correlation phenomenon that has not been described from first principles. Solid xenon bolometers, under development at Drexel University, are expected to have excellent counting statistics in the phonon channel, with energy resolution of 0.1% or better. This additional energy channel may offer the final piece of the puzzle in understanding liquid xenon detector energy response.

Speaker: Michelle Dolinski (Drexel University)

20150808_DPF.pdf

303 Development of a Photon Detection System in Liquid Argon for the Deep Underground Neutrino Experiment

The Deep Underground Neutrino Experiment (DUNE) will be a premier facility for exploring long-standing questions about the boundaries of the standard model. Acting in concert with the liquid argon time projection chambers underpinning the far detector design, the DUNE photon detection system will capture ultraviolet scintillation light in order to provide valuable timing information for event reconstruction. To maximize the active area while maintaining a small photocathode coverage, the experiment will utilize a design based on acrylic light guides coated with a wavelength-shifting compound, along with silicon photomultipliers, to collect and record scintillation light from liquid argon. We present performance measurements of this baseline design and an alternative design that utilizes a combination of wavelength-shifting plates and light guides and promises significant improvements in sensitivity to low-energy interactions.

Speaker: Dr Denver Whittington (Indiana University)

DPF-DUNE-PhotoDet-150804.pdf

304 The Mu2e electromagnetic calorimeter

The Mu2e experiment at Fermilab aims to measure the charged-lepton flavor violating neutrinoless conversion of a negative muon into an electron, producing a monochromatic electron with an energy slightly below the rest mass of the muon (104.97 MeV). We expect to set a limit on the ratio between the muon conversion and capture rate of 6.7 × 10^−17 at 90% CL in three years of running using a pulsed μ- beam that should provide ~10^18 stopped muons on an aluminum target. The calorimeter is designed to confirm that electron candidates reconstructed by the extremely precise tracker system are indeed conversion electrons, to provide stringent m/e particle identification and to provide a standalone, tracking independent, software trigger filter. It must also function in an environment in which the n, p and photon background from muon capture processes and beam flash events deliver a dose of as much as 120 Gy/year. It must also function in 1 T axial magnetic field and in a 10^−4 torr vacuum enclosure inside the Detector Solenoid. We therefore look for a calorimeter with a large acceptance for signal events, a reasonable energy O(5%) and time O(500 ps) resolution and a position resolution better than 1 cm to compare the impact point of the extrapolated tracks on the calorimeter surface. The Mu2e calorimeter design is two disks each with 900 BaF2 crystals. Each crystal is read out by two large area avalanche photodiodes (APD’s). These crystals match the requirements for stability of response, high resolution and radiation hardness. APD signals are amplified and shaped and then readout through 200 MSPS waveform digitizers optically connected to the DAQ system. We present the calorimeter design, the results obtained at 100 MeV with a LYSO prototype to test a first version of calorimeter system integration, and the R&D and simulation carried out to verify the design.

Speaker: Tomonari Miyashita

Miyashita.pdf

305 Studies of Beam Induced Radiation Backgrounds at the Mu2e Experiment and Implications for the Cosmic Ray Veto Detector Operations

The proposed Mu2e experiment will search for a neutrino-less muon to electron conversion process with almost four orders of magnitude of sensitivity improvement to the current best limit. One important background is caused by cosmic ray muons faking the conversion electron signature. In order to reach designed sensitivity, Mu2e needs to obtain a cosmic ray veto (CRV) efficiency of 99.99%. The CRV system consists of four layers of plastic scintillator which surrounds the detector, an area of approximately 300 m$^2$. One of the challenges the CRV system faces is the large neutron and gamma fluxes present in the experimental hall, produced from beam interactions. This radiation can damage the detector components and generate large background noise in the CRV. We estimate the noise and total dead-time produced by the radiation backgrounds in the CRV using Geant4 based simulation with complete Mu2e experiment geometry and realistic CRV response.

Speaker: Dr Yuri Oksuzian (University of Virginia)

DPF2015_CRV_Deadtime .key.zip

DPF2015_CRV_Deadtime .pdf

306 Progress on the development of 6 cm × 6 cm microchannel plate photodetectors at Argonne National Laboratory

Micro-channel plate (MCP)-based photodetectors simultaneously provide picosecond level time resolution, sub-mm level position resolution and high rate capability. The large-area picosecond photodetector (LAPPD) collaboration is developing new techniques to make large-area MCP- based photodetectors. Recently, Argonne National Laboratory (ANL) commissioned a photodetector processing system for producing small form factor, high quantum efficiency, 6 cm × 6 cm photodetectors based on Atomic Layer Deposition (ALD) functionalized MCPs and low cost glass packaging. Here we report the successful production of the first devices that are fully processed and hermetically sealed. We have measured quantum efficiency higher than 15%, gain of up to 107, single photoelectron time resolution of 57 ps, and position resolution better than 1 mm. The experience gained from this processing system will be transferred to industry for production towards larger area. The progress on the photocathode study, the photodetector production, the testing and characterization will be presented.

Speaker: Jingbo Wang (Argonne National Laboratory)

dpf2015_ANL_photodetectors.pdf

15:30 Cafe Break

Education and Outreach

307 The International Particle Physics Outreach Group

The International Particle Physics Outreach Group (IPPOG) contributes to global efforts in public outreach and science education that support particle physics. Membership includes scientists, researchers, science educators and explainers from prominent laboratories and institutions engaged in particle physics. IPPOG supports International Masterclasses in which annually about 10,000 high school students in 42 countries come to one of about 200 nearby universities or research centers for one day to unravel the mysteries of particle physics. The online IPPOG Resources Database, a repository of activities, programs, events and resources. We encourage members of the particle physics community to make contributions to the database and search the contents for outreach ideas.

Speaker: Marjorie Bardeen (Fermilab)

DPF 2015 talk.pdf

308 Discovery and the QuarkNet Data Portfolio

QuarkNet has assembled a Data Portfolio, a collection of activities following best practices and based on the use of authentic data from experiments. One of the key themes of these activities is the ability of students to discover particle physics that is new to them. We will look at the Data Portfolio as a whole and zoom in on one activity, Plotting LHC Discovery.This activity enables students to "discover" a well-known particle in a mass plot and then apply what they have learned to an actual recent particle discovery. In this case, students examine dimuon mass plots for the J/Ψ meson and the recent CMS-LHCb combined rare B meson result. Kenneth Cecire is a QuarkNet National Staff Teacher at the University of Notre Dame with over 20 years experience in teaching and 16 years on the QuarkNet staff.

Speaker: Kenneth Cecire (University of Notre Dame)

slides_cecire_dpf2015.pdf

slides_cecire_dpf2015.pptx

309 Reaching the Public with Science Festivals

Science Festivals are booming in the U.S. and around the world. This presentation will offer lessons learned from three USA Science and Engineering Festivals and three Michigan State University Science Festivals. Participants should expect to get tools and advice for starting and populating Festival events. Zachary Constan earned his Ph.D. in physics at Michigan State University, and now serves as the Outreach Coordinator for the National Superconducting Cyclotron Laboratory.

Speakers: Ms Renee Leone (Michigan State University), Zach Constan (National Superconducting Cyclotron Laboratory)

APS Renee Leone Zach Constan 8-7-15.pptx

MSU Science Festival website

310 How to run a science cafe

Science cafes are informal public events in which scientists and other professional researchers gather to present and/or discuss current research with members of the lay public. Science cafes are most frequently geared towards adults, but can be designed for other age ranges. During this session, RELATE Co-Founders Elyse Aurbach and Katherine Prater will describe how to start a science cafe series, including a discussion about the most valuable components for a successful event. RELATE is a science communication training and public engagement initiative that facilitates conversations between researchers and local communities. During our practice-based workshop, graduate students and early career researchers develop lay-audience communication skills and create an original portfolio of digital media and oral presentations. Workshop participants put their communication skills into action and engage with Southeastern Michigan communities both online and through our public engagement events. Elyse Aurbach and Katherine Prater are co-founders of RELATE and current PhD candidates in Neuroscience at the University of Michigan.

Speakers: Elyse Aurbach (University of Michigan), Katherine Prater (University of Michigan)

How to run a science cafe_v4.pptx

Field and String Theory

Conveners: Christopher Herzog (Stony Brook University), David Berenstein (University of California at Santa Barbara)

311 On the classification of 4d rank1 N=2 SCFT

I will report on a systematic approach to the classification of four dimensional N=2 superconformal field theories (SCFTs) with a one dimensional moduli space of Coulomb vacua with planar topology. The geometric structure of the Coulomb branch encodes ultraviolet conformal field theory data: the relevant mass deformations of the UV N=2 SCFTs are mapped to the complex deformations of singular Coulomb branch geometries. Our results go beyond the standard lore of the ADE classification, and a richer pattern of flavor symmetries is revealed corresponding to different deformations. We have constructed explicit Seiberg-Witten (SW) curves and one-forms for each possible regular deformation. Further physical consistency conditions are obtained by considering N=2 RG flows, and certain SW geometries are ruled out by our conjecture about the absence of dangerously irrelevant operators in N=2 field theories. All but one of the surviving SW geometries correspond to known N=2 SCFTs; we conjecture that the new geometry corresponds to a previously undiscovered rank 1 N=2 SCFT. The structure of the enhanced Coulomb branches (also known as mixed branches) of these N=2 SCFTs is also examined in terms of N=1 chiral ring relations. The related data (i.e., the dimension of the Higgs branch factor) is used to compute the conformal and flavor central charges by a refined version of Shapere and Tachikawa's topological twisting argument.

Speaker: Yongchao Lv

DPF2015-Yongchao Lu.pdf

312 T-duality off shell in 3D Type II superspace

We give the manifestly T-dual formulation of the massless sector of the classical 3D Type II superstring in off-shell 3D N = 2 superspace, including the action. It has a simple relation to the known superspace of 4D N = 1 supergravity in 4D M-theory via 5D F-theory. The prepotential appears as part of the vielbein, without derivatives.

Speaker: Mr Martin Polacek (PhD student)

Pra_New.pdf

313 Thermalization in the D1D5 Black Hole

The traditional picture of a black hole as a point-like singularity with no structure at the horizon is known to emit Hawking radiation in a non-unitary fashion. The fuzzball proposal attempts to resolve this dilemma by treating the black hole as a large bound string state with structure at the horizon and a "bubble of nothing" in the interior. There has been much success in matching the microscopic structure of this model with known results from black hole thermodynamics, though a detailed description of black hole formation has not yet been found. As a step towards this, we look at the process of an infalling quanta reaching the black hole and thermalizing, allowing it to be re-emitted later as low-energy Hawking radiation.

Speaker: Zaq Carson (The Ohio State University)

DPF Presentation.pdf

314 Thermal Corrections to Renyi Entropies on the n-Sphere

Interest in entanglement entropy and its generalization Renyi entropy is growing due to its applications in a variety of fields in physics, from quantum computation and phase transitions to black hole physics and holography. In this talk I will discuss the effects of a small finite temperature on both measures of entanglement. The primary focus will be on calculating corrections for a free fermion on an n-sphere. Via conformal maps and a Boltzmann expansion of the density matrix, the corrections can be related to a specific two point function on a conical space. This work expands on previous work in Refs. arXiv:1407.1358 and arXiv:1411.6505.

Speaker: Michael Spillane (Stony Brook University)

DPF2015.pdf

315 Spinning the fuzzy sphere

We construct various exact analytical solutions of the $SO(3)$ BMN matrix model that correspond to rotating fuzzy spheres and rotating fuzzy tori. After an appropriate ansatz, we reduce the problem to solving a set of polynomial equations in $2N$ real variables. These equations have a discrete set of solutions for each value of the angular momentum. We study the phase structure of the solutions for various values of $N$, as well as the large $N$ limit. In this limit the problem reduces to finding periodic solutions of a set of coupled non-linear differential equations with a fixed period. We also study the topology change transition from the sphere to the torus.

Speaker: Prof. David Berenstein (UCSB)

Berenstein_DPF2015.pdf

Spinning the Fuzzy Sphere -- original paper link

AstroParticle, Cosmology, Dark Matter Searches, and CMB

Convener: Orin Harris (Indiana University South Bend)

316 Status of the MiniCLEAN Experiment

Single-phase liquid argon detectors offer a technically simple approach towards a very massive detector for the direct detection of dark matter with potential to extend sensitivity into the “background floor” imposed by the coherent scattering of extraterrestrial neutrinos. MiniCLEAN, with a target mass of 500 kg, serves as a prototype to demonstrate this approach. Event energy and position are reconstructed in three dimensions and a powerful means of pulse-shape discrimination separates nuclear recoil events from electromagnetic background. The MiniCLEAN experiment is now being commissioned at the 6800 foot level in SNOLAB’s Cube Hall. We will provide a status report and plans for the MiniCLEAN experiment.

Speaker: Tom Caldwell (University of Pennsylvania)

dpf_2015_tcald.pdf

317 Commissioning Data Results for the DEAP-3600 Dark Matter Experiment

The DEAP-3600 experiment uses 3.6 tons of liquid argon for a sensitive dark matter search, with a sensitivity to the spin-independent WIMP-nucleon cross-section of 10^{-46} cm^2 at 100 GeV WIMP mass. This high sensitivity is achievable due to the large target mass and the very low backgrounds in the spherical acrylic detector design as well as at the unique SNOLAB facility in Sudbury, Canada. The liquid argon target is enclosed in an ultra pure acrylic vessel. 255 high efficiency photomultiplier tubes collecting scintillation light are separated from the argon through acrylic light guides and polyethylene filler blocks, providing neutron shielding and thermal insulation. Pulse shape discrimination is used to reject electromagnetic backgrounds from the WIMP induced nuclear recoil signal. We started taking commissioning data in February 2015 with vacuum and later gas inside the detector. Liquid argon fill is expected in mid 2015. In this talk we will present results from analysis of the commissioning data.

Speaker: Bei Cai (Queen's University)

DEAP3600_BeiCai_DPF2015.pdf

318 Status and Results from DarkSide-50

DarkSide-50 is the first physics detector of the DarkSide dark matter search program. The detector features a dual-phase underground-argon Time Projection Chamber (TPC) of 50 kg active mass surrounded by an organic liquid-scintillator neutron veto (30 tons) and a water-Cherenkov muon detector (1000 tons). The TPC is currently fully shielded and operating underground at Gran Sasso National Laboratory. A first run of 1422 kg-day exposure with atmospheric argon represents the most sensitive dark matter search using a liquid argon target. The TPC is now filled with underground argon, greatly reduced in Ar-39, and DarkSide-50 is in its final configuration for an extended dark matter search. Overviews of the design, performance, and results obtained so far with DarkSide-50 will be presented, along with future prospects for the DarkSide program.

Speaker: Alden Fan (UCLA)

DPF2015_DS50_AFAN.pdf

319 The LUX Dark Matter Experiment and an Updated Analysis of Its First Results

The Large Underground Xenon (LUX) experiment is working on the detection of dark matter particles through their possible weak interactions with heavy nuclei. LUX is a dual phase time projection chamber (TPC) filled with 350kg of liquid Xenon and located 5000 feet underground at the Sanford Underground Research Facility (SURF). It uses the ratio of the primary scintillation and secondary ionization signals from particle interactions with Xe nuclei to discriminate between electron-recoil backgrounds and nuclear-recoil WIMP signatures. In addition, the reconstructed three-dimensional position of these interactions and xenon's effective self-shielding is further used to suppress backgrounds originating from outside of the TPC. An overview of the LUX experiment will be presented here along with the updated results from a recent re-analysis of previously reported data using improved calibrations and data processing chain.

Speaker: Tomasz Biesiadzinski

aps-dpf_TomaszBiesiadzinski_150731_v5.pdf

320 Progress of the LZ Dark Matter Experiment

LZ is the successor experiment to LUX, the current most sensitive dark matter detector operated at Sanford Lab in South Dakota. It is a 20x upgrade in target mass with a goal of 100x improvement in WIMP-nucleon cross-section sensitivity after three years of data. The design of the experiment is well advanced and critical technology demonstrations are underway. Here we present relevant elements of design and simulation outputs, outline the expected timetable through commissioning and make the case for how LZ can reach a sensitivity of ~2e-48 cm2 at 50 GeV WIMP mass.

Speaker: Carter Hall (University of Maryland)

Hall-LZ-DPF2015.pdf

Hall-LZ-DPF2015.pptx

321 The PandaX Dark Matter Experiment

The PandaX Collaboration has designed and constructed dual-phase xenon detectors to search for Weakly Interacting Massive Particles (WIMPs), which is a leading dark matter candidate. We have reported the first 17.4 live-day and full 80.1 live-day exposure results of the first stage of the PandaX experiment (PandaX-I) located in China JinPing Underground Laboratory (CJPL). With a fiducial mass of 54.0kg liquid xenon, no dark matter particle event was found above the expected background. Our results disfavor the interpretation of previously reported positive low-mass WIMP signals and set a stringent bound in this region. The second stage of the PandaX experiment (PandaX-II) with 500-kg sensitive target mass is under preparation in CJPL. With larger sensitive mass and lower background materials for the detector, the PandaX-II detector is expected to push the dark matter sensitivity beyond the current best limit in a wide range of WIMP masses.

Speaker: Andi Tan

TAN_DPF2015.pdf

322 Scintillating Bubble Chambers for Direct Dark Matter Detection

The scintillating bubble chamber has the potential to be an incredibly powerful new tool for dark matter detection. Combining the world-leading electron recoil rejection of a bubble chamber with the energy information available in a liquid scintillator, these devices should achieve unprecedented discrimination against all backgrounds while working with a variety of target materials. New possibilities include xenon-based detectors with 10^10 discrimination against electron recoils, argon-based detectors with discrimination down to few-keVr (or even sub-keVr) thresholds, and organic and fluorinated-organic scintillator detectors immune to the alpha-induced backgrounds that likely limit existing bubble chamber experiments. We'll present progress by groups at SUNY Albany and Northwestern University towards the world's first working scintillating bubble chambers, starting with liquid xenon targets. With the potential to cover spin-dependent, spin-independent, and low-mass WIMPs, and the scalability already demonstrated by both bubble chambers and liquid scintillators, this technology could rapidly become a contender for G3 dark matter searches.

Speaker: Matthew Szydagis (University at Albany)

SzydagisDPFConference.pdf

Neutrino Physics

323 Muon neutrino disappearance at NOvA

NOvA is a long-baseline (810 km) neutrino oscillation experiment utilizing the recently upgraded NuMI beam at Fermilab and a highly segmented 14 kton liquid scintillator far detector 14 mrad off beam axis at Ash River, MN. NOvA will provide high precision measurements of ${\Delta}M^2_{23}$, ${\theta}_{13}$, and ${\theta}_{23}$; help constrain ${\delta}_{CP}$; and potentially determine the mass hierarchy and the octant through both disappearance and appearance channels. The current status of the disappearance analysis will be presented, focused on measuring ${\Delta}M^2_{23}$ and ${\theta}_{23}$ with NOvA's first data.

Speaker: Kirk Bays

NOvA_Disappearance_Analysis.pdf

324 Extrapolation techniques and systematic uncertainties in the NOvA muon neutrino disappearance anaysis

The NOvA long-baseline neutrino experiment consists of two highly active, finely segmented, liquid scintillator detectors located 14 mrad off Fermilab's NuMI beam axis, with a Near Detector located at Fermilab, and a Far Detector located 810 km from the target at Ash River, MI. The experiment is sensitive to the muon neutrino disappearance parameters sin^2(theta_23) and delta m^2_(32) through the measurement of the modulation of the muon neutrino spectrum between the Near and Far Detectors. This talk will present a discussion of the systematic uncertainties associated with with the analysis of data collected to date, and the methods developed to predict the Far Detector spectrum as extrapolated from the observed Near Detector data.

Speaker: Dr Louise Suter (Argonne National Lab.)

DPF_suter.pdf

325 Electron Neutrino Identification and First Results of the NuE Appearance Analysis at NOvA

The NOvA experiment is a long-baseline accelerator based neutrino oscillation experiment. It uses the upgraded NuMI beam from Fermilab and measures electron neutrino appearance and muon neutrino disappearance at its Far Detector in Ash River, Minnesota. The NuE appearance analysis at NOvA aims for resolving mass hierarchy and the CP violating phase. This talk will present first results from NOvA’s electron appearance analysis. The first task of the NuE appearance analysis is to identify electron neutrino events from various backgrounds. This talk will also review major particle identification and event reconstruction techniques for the NuE appearance analysis at NOvA experiment.

Speaker: Jianming Bian (University of Minnesota)

nova_nue_DPF2015_08_07.pdf

326 Cosmic Ray Background Rejection in NOvA

The Numi Off-axis Neutrino Appearance (NOvA) experiment measures electron neutrino appearance at a distance of 810 km from where muon neutrinos are generated. The experiment consists of two functionally identical detectors, a Near Detector (ND) at Fermilab and a Far Detector (FD) at Ash River in Northern Minnesota. The detectors are fully commissioned and have been taking beam neutrino data since 2014. The FD is located on the surface, under 14 radiation lengths of barite and concrete overburden. Abundant cosmic rays passing through the FD present a unique challenge in cosmic ray background rejection. The cosmic background rejection in the FD is done in two steps: first, a set of cosmic ray veto cuts common to all NOvA beam neutrino analyses are applied, then additional, analysis specific cuts are applied. This talk will focus on the latter step of the rejection stream, the cosmic rejection cuts designed specifically for the study of electron neutrino appearance analysis in NOvA. The cosmic background to signal ratio is reduced significantly and the figure of merit increases after the cuts are applied.

Speaker: Tian Xin (Iowa State University)

20150807_txin_CosmicRejection.pdf

327 Muon Induced EM Showers in NOvA Detectors

The NOvA experiment is an electron neutrino appearance neutrino oscillation experiment at Fermilab. Electron neutrino events are identified by the electromagnetic (EM) showers induced by electrons in the final state of neutrino interactions. EM showers induced by cosmic muons or rock muons, are abundant in NOvA detectors. We use a Muon-Removal Technique to get pure EM shower samples from cosmic and rock muon data. Those samples can be used to characterize the EM signature and provide valuable checks of the MC simulation, reconstruction, PID algorithms, and calibration across the NOvA detectors.

Speaker: Hongyue Duyang (University of South Carolina)

dpf2015_cosmicmr.pdf

328 Predicting the Far Detector Event Rate in the NOvA Electron Neutrino Appearance Channel

The NOvA experiment is a long-baseline, two detector experiment designed to study the electron neutrino appearance channel. In this talk, we discuss how we use our Near Detector data to predict signal and background rates at the Far Detector after NOvA's first year of data taking. To determine our background, the neutrino interactions that pass the electron neutrino selection must be broken down by neutrino interaction type, as each type oscillates differently while traveling to the Far Detector. In the simplest approach, we use the Near Detector data as an overall normalization correction to the Monte Carlo expectation for each of the sample components. Two other techniques, one based on hadronic shower comparisons and another based on Michel electron tagging, are still under development and provide valuable cross checks. Our signal prediction is based on muon neutrino charged current interactions selected in the Near Detector, after an efficiency and cross section correction. We then discuss how the component-by-component Near Detector observations are translated into predictions in this data-driven framework.

Speaker: Daniel Pershey

DPF2015_NOvA_NueExtrapolation.pdf

329 Implementation of an upward-going muon trigger for indirect dark matter searches at the NOvA far detector

The NOνA collaboration has constructed a 14,000 ton, fine-grained, low-Z, total absorption tracking calorimeter at an off-axis angle to an upgraded NuMI neutrino beam. This detector, with its excellent granularity and energy resolution, and relatively low-energy neutrino thresholds was designed to observe electron neutrino appearance in a muon neutrino beam, but it also has unique capabilities suitable for more exotic efforts. In fact, if an efficient upwardgoing muon trigger with sufficient cosmic ray background rejection can be demonstrated, NOνA will be capable of a competitive indirect dark matter search for low-mass WIMPs. The cosmic ray muon rate at the NOνA far detector is about 100 kHz and provides the primary challenge for triggering and optimizing such a search analysis. The status of the NOνA upward-going muon trigger is presented.

Speaker: Robert Mina (University of Virginia)

upmu_dpf2015.pdf

EWK and Higgs Sector: Future Prospects

Convener: Jim Brau (University of Oregon (US))

330 Probing Flavon-Higgs mixing effects at future colliders

Current measurements of the Higgs properties at LHC seem consistent with the Standard Model. The couplings with fermions and gauge bosons, when taken as function of the particle mass, should lay on a single line. However, in models with extended Higgs sector the diagonal Higgs couplings to fermions, could lay on different lines, while non-diagonal flavor-violating Higgs couplings could appear too. We describe these possibilities within the context of multi-Higgs doublet models that employ the Froggart-Nielsen mechanism to generate the Yukawa hierarchies. Furthermore, one of the doublets can be choosen to be of the inert type, which provides a viable dark matter candidate. The mixing of the Higgs doublets with the Flavon field, can provide plenty of interesting signals, including: i) small corrections to the couplings of the SM-like Higgs, ii) exotic signals from the flavon fields, iii) new signatures from the heavy Higgs bosons. These aspects are studied within a specific model with 3+1 Higgs doublets and a singlet FN field. Constraints on the model are derived from the Higgs search at LHC, and their implications for the LFV Higgs decay H_i -> tau mu and the FCNC top decay $t\to ch$, are presented too.

Speaker: Prof. Lorenzo Diaz-Cruz (FCFM BUAP (Mexico))

Diazcruz-DPF15.pdf

331 Higgs Production at Extremely Large Transverse Momentum

A future 100 TeV collider provides the opportunity to study the production of Higgs at large transverse momentum $p_T$. The effective field theory for Higgs, obtained by integrating out the top quark, breaks down when $p_T$ is larger than 200 GeV. We calculate the $p_T$ distribution at much larger $p_T$ using the framework of factorization, in which the cross section is expressed as convolutions of hard-scattering cross sections and fragmentation functions, with the leading logarithms of $p_T^2/m_t^2$ resummed to all orders. By separating the scales $m_t$ and $p_T$, the higher order radiative correction can be greatly simplified.

Speaker: Hong Zhang

DPF_Hong_Zhang.pdf

332 The Higgs Physics Program at the International Linear Collider

The precise exploration of all aspects of the Higgs sector is one of the key goals for future colliders at the Energy Frontier. The International Linear Collider (ILC) provides the capability for model-independent measurements of all relevant couplings of the Higgs boson to fermions and gauge bosons, including direct measurements of the Top Yukawa coupling as well as of the Higgs self-coupling. This contribution will review the highlights of Higgs physics at the ILC in the context of a 20-year-long physics program. This program covers different collision energies up to 500 GeV with various beam polarisations, each contributing important aspects to the exploration of this new sector of particle physics. Beyond this initial scope of the ILC, we will also discuss the prospects of a 1 TeV upgrade, which offers complementary capabilities for the measurement of double Higgs production and the Higgs self-coupling.

Speakers: Jan Fridolf Strube, Jan Fridolf Strube (CERN), Jan Fridolf Strube

HigssAtILC_DPF2015_PNNLTemplate.pdf

HigssAtILC_DPF2015_PNNLTemplate.pptx

Quark and Lepton Flavor Physics

333 Study of Bc Mesons at LHCb

Speaker: Lucio Anderlini (Universita e INFN, Firenze (IT))

ANDERLINI-DPF4.pdf

334 Study of baryonic decays of B mesons at BABAR

Speaker: David Norvil Brown (University of Louisville (US))

DNB_DPF_B2BTalk15_v2.pdf

335 Update on e+e− → π+π−ψ(2S) via initial state radiation at Belle

Speaker: Xiaolong Wang (VirginiaTech)

dpf2015-wxl.pdf

BSM Physics

336 Color Discriminant Variable to Separate Dijet Resonances at the LHC

A vector resonance decaying to dijets could be discovered at the 14 TeV run of the LHC. To quickly identify its color structure in a model-independent manner, we introduce a method based on the color discriminant variable, determined from the measurements of the resonance's dijet cross section, mass and width. This talk illustrates how the cross section measurements of the resonance's heavy-flavor decays help distinguish between a color-octet vector boson and leptophobic color-singlet one, where both could have flavor non-universal couplings to quarks. The method is generally applicable although couplings to light quarks are inaccessible to experiments, and the color-singlet could have non-standard invisible decays.

Speaker: Pawin Ittisamai (Michigan State University)

ittisamai-dpf2015.pdf

337 Anatomy of Coannihilation with a Scalar Top Partner

We present a simplified dark matter model where a Majorana fermion χ coannihilates with a colored scalar top partner t˜. We explore the cosmological history, with particular emphasis on the most relevant low-energy parameters: the mass splitting between the dark matter and the coannihilator, and the Yukawa coupling that connects these fields to the Standard Model top quarks. We also allow a free quartic coupling between a pair of Higgs bosons and t˜ pairs. We pay special attention to the case where the values take on those expected where t˜ corresponds to the superpartner of the right-handed top, and χ is a bino. Direct detection, indirect detection, and colliders are complementary probes of this simple model. We will also discuss implications for stop conannihilations within the MSSM.

Speaker: Prof. Aaron Pierce (University of Michigan)

Pierce_DPF2015.pdf

338 Anatomizing BSM effects with differential Higgsstrahlung observables

New physics beyond the Standard Model could give rise to modifications of the Higgs couplings properly described in an effective field theory approach. With respect to the SM gauge symmetry, such effects are expressed by dimension-six or higher operators after integrating out heavy particles or loop functions. The operators modifying Higgs to ZZ couplings are naturally of particular interest. This is partly because this coupling will be one of the most precisely determined quantities through a recoil-mass measurement and partly because it is one of the key couplings that could help reveal the underlying dynamics of electroweak symmetry breaking. We study the potential diagnostic power of electron-positron colliders on these operators through various differential cross sections and asymmetries. We expand the scope of the conventional precision Higgs at electron-positron colliders into interaction Lorentz structure tests. We further discuss the complementarity between electroweak precision observables and Higgs observables. Our study sharpens the BSM physics potential at electron-positron Higgs factories.

Speaker: Zhen Liu

ZhenLiu_DPF2015_HZll.pdf

339 Neutrino Masses and Sterile Neutrino Dark Matter from the PeV Scale

The Higgs boson mass of 125 GeV is suggestive of superpartners at the PeV scale. This talk discusses how new physics at this scale can also produce active neutrino masses via a modified, low energy seesaw mechanism and provide a sterile neutrino dark matter candidate with keV-GeV scale mass. Possible connections to the 3.5 keV X-ray line and the PeV neutrino events at IceCube will also be discussed.

Speaker: Bibhushan Shakya (MCTP)

Bibhuhan DPF 2015.pdf

Accelerators, Detectors, Computing

Conveners: Daniel Winklehner (Massachusetts Institute of Technology), Joel England (Stanford)

340 High-efficiency acceleration of an electron beam in a plasma wakefield accelerator.

With the size and cost of high energy physics machines rapidly approaching the logistical limits of feasibility, a fundamentally new method for accelerating particles up to very high energies will be required if we wish to continue to push at the boundaries of the energy frontier. Two key factors tend to dominate the estimated cost of future collider designs: the overall size of the machine, and the power consumption. Plasma wakefield acceleration is a forefront electron and positron acceleration technology that addresses both of these factors simultaneously by providing extremely high accelerating gradients and a high energy transfer efficiency from the accelerator to the beam. In this talk, I will present results from SLAC National Accelerator Laboratory’s Facility for Advanced Accelerator Experimental Tests (FACET), where the acceleration of a bunch of electrons in a high gradient, high efficiency plasma wakefield accelerator driven by a high peak-current electron beam has been demonstrated for the first time.

Speaker: Dr Michael Litos (Stanford University)

APS DFP 2015 Litos.pdf

341 Future Accelerator Facilities for High Energy Physics Research

With the discovery of the Higgs boson at the LHC, the picture of the Standard Model of particle physics is complete. However, there are strong theoretical motivations and experimental indicators for new physics beyond the standard model. Therefore, there are various plans underway around the globe for future facilities for high energy physics research. Extending the energy frontier beyond the LHC will be vital to elucidate the nature of electroweak symmetry breaking and whatever new physics that might be found at the LHC in the 13 TeV run that is now beginning. Very large hadron colliders in large circular rings of ~100 km or more in circumference, e+e- colliders (linear or circular) and a mu+mu- collider have all been proposed for various sites in Europe, US, and Asia to continue the pursuit of high energy physics. New physics beyond the Standard Model will also require pursuing research in the neutrino sector and in studies of rare decays. I will discuss the possible scenarios, design issues and technological challenges for hadron colliders and for e+e- colliders and also briefly discuss accelerator facilities for the neutrino programs being planned. It is critical that the high energy physics community be engaged in driving the development of these future facilities.

Speaker: Pushpalatha Bhat (Fermi National Accelerator Lab. (US))

PushpaBhat_FutureAcc_DPF2015.pdf

PushpaBhat_FutureAcc_DPF2015.pptx

342 Particle Acceleration - Laser Wakefield Experiments at U. Michigan

Presented here is an overview of laser wakefield accelerator (LWFA) experiments at the University of Michigan using the HERCULES and Lambda-Cubed high power laser systems. In our experiments, up to GeV energy electrons are generated in a cm scale plasma based accelerator. We show how using multi-stage gas cells result in increased stability and reproducibility. Annular quasimonoenergetic electron beams with mean energy in the range 200 − 400 MeV and charge on the order of several pC were generated using laser wakefield acceleration in a two-stage gas cell. Generation of these annular beams is associated with transverse injection occurring on the density downramp between stages. This well-localized injection produces a bunch of electrons performing coherent betatron oscillations in the wakefield resulting in a significant increase in the X-ray yield. Such ultrafast X-rays may lead to tabletop synchrotron light sources. We also use a high repetition rate to investigate the coherent control of the plasma dynamics by feedback-optimized wavefront manipulation using a deformable mirror. The demonstration of coherent control for plasmas opens new possibilities for future laser-based accelerators and their applications.

Speaker: Alexander Thomas (university of michigan)

Thomas_DPF_2015.pdf

343 “TeV on a chip”: X-ray wakefield accelerator in nanomaterials

The laser-driven acceleration such as LWFA (laser wakefield acceleration) has demonstrated its capability of accelerating electrons (and other charged particles) to high energies over a very compact distance two-three orders of magnitude shorter than the conventional accelerator methods. Thus the typical LWFA experiments conducted in a gas plasma of density ~ 1018 /cc gain energies of GeV over a matter of cm. The LWFA energy gain is inversely proportional to the plasma density Δε = 2mc2 a02 (ncr / n), where mc2 is the electron rest mass energy, a0 is the normalized vector potential, ncr the critical density (1021 /cc for a 1eV optical laser), and n is the electron density. On the other hand, the accelerating length of LWFA over one stage scales inversely proportional to the density power of n-3/2, making it longer for lower densities [Tajima/Dawson, 1979]. The introduction of a newly discovered path with X-ray (~10keV) laser pulses [Mourou et al., 2014] allows us for the first time to choose an alternative and even more attractive path toward ultrahigh energies as an experimental possibility [Tajima, 2014]. Previously we lacked realistic X-ray drivers. Since the critical density ncr is proportional to the frequency of the laser squared ω02 , for the X-ray laser at 10keV, for example, the critical density is as large as ncr = 1029 /cc. This is why we now can choose a solid density (1023 /cc) material such as nanomaterials in place of gas plasma, leading to the prospect of an immense energy gain (TeV) over mere cm. In addition, we will discuss additional novel developments and applications of wakefield acceleration. T. Tajima and J. M. Dawson, PRL 43, 267 (1979). G. Mourou, et al., Eur. Phys. J. 223, 1181 (2014). T. Tajima, Eur. Phys. J. 223, 1037 (2014).

Speaker: Dr Toshiki Tajima (UCI)

04-APSDPF15.pptx

344 High-Gradient, Millimeter Wave Accelerating Structure

The millimeter wave all-metallic accelerating structure, aimed to provide more than 100 MeV/m gradient and fed by feeding RF pulses of 20-30 ns duration, is proposed. The structure is based on a waveguide with small helical corrugation. Each section of 10-20 wavelengths long has big circular cross-section aperture comparable with wavelength. Because short wavelength structures are expected to be critical to wakefields excitation and emittance growth, we suggest to combine in one structure properties of a linear accelerator and a cooling damping ring simultaneously. It provides acceleration of straight on-axis beam as well as cooling of this beam due to the synchrotron radiation of particles in strong non-synchronous transverse fields. These properties are provided by specific slow eigen mode which consists of two partial waves, TM01 and TM11. Simulations show that shunt impedance can be as high as 100 MOhm/m. Results of the first low-power tests with 30 GHz accelerating section are analyzed.

Speaker: Dr Sergey Kuzikov (Institute of Applied Physics)

Helical acc str.pdf

Helical acc str.pptx

345 Two-Beam-Acceleration Experiments at the Argonne Wakefield Accelerator Facility (AWA)

The Argonne Wakefield Accelerator Facility develops technology for future HEP accelerators. Its main focus is on the use of electron beam driven wakefield acceleration using RF structures. A high intensity electron linac is used to drive wakefields, and a second electron linac provides electron bunches to be accelerated by these wakefields. Recent two-beam-acceleration (TBA) experiments have demonstrated accelerating gradients higher than 50 MV/m, while preserving the beam quality of the accelerated bunches. Further experiments aim at surpassing 100 MV/m gradients and achieving net energy gains of more than 100 MeV. Demonstration of successive acceleration using two TBA stages will follow shortly.

Speaker: Manoel Conde (Argonne National Laboratory)

DPF2015_talk_conde.pdf

DOE Program: HEP Theory

Convener: Simona Rolli

346 HEP Theory

Speaker: Simona Rolli

Theory-PI-Meeting-August2015.pdf.pdf

18:45 Conference Banquet at Museum of Art

Saturday 8 August

07:30 Breakfast

Session I-E

Convener: Prof. Daniela Bortoletto (University of Oxford (GB))

347 Future Accelerators

Speaker: Pushpalatha Bhat (Fermi National Accelerator Lab. (US))

DPF2015_Shiltsev_BHAT_v2.pdf

DPF2015_Shiltsev_BHAT_v2.pptx

348 The Future (Near and Far) of Particle Detectors

The field of particle physics spans 24 orders of magnitude in energy – from axion masses to the highest energy cosmic rays. The species of particles we have to contend with – hadrons, leptons, bosons, neutrinos, dark matter, phonons, quasi-particles, etc. – are unique and equally challenging in nature. Because of this diversity, particle physics has traditionally been a hotbed of innovative detector research. This talk will cover some of the challenges facing us today in detector technology and overview some of the most interesting solutions to those challenges.

Speaker: Erik Ramberg (Fermilab)

Future Detectors - DPF meeting - UM.pptx

349 The Vision of CERN

The recent update of the European Strategy for Particle Physics set the direction for the further development of the field in Europe for the coming years. The medium and longer-term plans of CERN are fully aligned with this strategy. The vision of CERN as part of a global collaboration will be outlined covering 4 main areas: the full exploitation of the LHC, studies at the future energy frontier, participation in future international neutrino facilities and diversity programs making use of the unique facilities available at CERN.

Speaker: Paul Collier (CERN)

150808-DFP2015.pdf

150808-DFP2015.pptx

350 FNAL Vision

Speaker: Joseph David Lykken (Fermi National Accelerator Lab. (US))

lykken_DPF_8-2015.pdf

10:30 Cafe Break

Session II-E

Convener: Myron Campbell (High Energy Physics)

351 The U.S. High Energy Physics Program in a Global Vision of Particle Physics

The DOE Office of High Energy Physics is continuing to implement the global vision for particle physics presented in the May 2014 report of the Particle Physics Project Prioritization Panel (P5). Widespread support from the U.S. and international particle physics communities has enabled rapid progress for key elements of the program envisioned by P5 and will continue to be crucial to successfully implementing the strategy moving forward. I will discuss how the DOE High Energy Physics program is executing its mission in coordination with domestic and international partners in order to pursue the five intertwined science drivers and enable discovery at the frontiers of particle physics.

Speaker: Jim Siegrist (DOE)

2015-08-08 DOE HEP Program in a Global Vision of Particle Physics.pdf

352 Maintaining the Visibility of the P5 Report

Speaker: Steven Ritz (UCSC)

DPF-P5-Ritz-v1a.pdf

353 P5: One Year Later

Speaker: Andrew James Lankford (University of California Irvine (US))

150508 DPF - Lankford.pdf

354 Status of the NSF Particle Physics program

A brief history of the NSF Elementary Particle Physics (EPP) program will be presented. This will show current research areas being funded. In addition I will show the status of upcoming solicitations: CAREER, MRI, 2016 EPP and Accelerator Science. I will describe other EPP projects funded under the Mid-Scale program and talk about the prospects for the near-term future in this program. The current state of the new (now in the second year) Accelerator Science program in the NSF PHY division will be presented. I will talk about current funding initiatives involving computing related to the EPP program. Finally, I will discuss the status of the Major Research Equipment and Facilities Construction (MREFC) process as it relates to the LHC Phase II upgrades.

Speaker: Jim Shank (Boston University (US))

DPF_UM_shank.pdf

355 Closing Statement from Scientific Committee Chair

Speaker: Myron Campbell (University of Michigan)