DPF 2011

Aug 8, 2011, 6:00 PM → Aug 13, 2011, 4:00 PM US/Eastern

Rhode Island Convention Center

David Cutts (Department of Physics-Brown University-Unknown), Meenakshi Narain (Brown University), Ulrich Heintz (Department of Physics-Brown University)

2011 Meeting of the Division of Particles and Fields of American Physical Society (see http://www.hep.brown.edu/~DPF2011/)

Monday, August 8

Registration

Tuesday, August 9

8:00 AM Breakfast

Plenary Session

Convener: Ulrich Heintz (Department of Physics-Brown University)

1 Welcome

Speaker: Prof. James Valles (Chair Physics Department - Brown University)

Slides Valles_DPF_Welcome_Talk_2011.pdf Valles_DPF_Welcome_Talk_2011.ppt

2 Welcome

Speaker: Prof. Clyde Briant (Vice President for Research (Brown University))

3 Electroweak Physics

Speaker: Michael Henry Schmitt (Department of Physics and Astronomy-Northwesten University)

Slides 30_MichaelSchmitt.pdf

4 Beyond the Standard Model: theory

Speaker: Konstantin Matchev (Department of Physics-University of Florida)

Slides http://www.phys.ufl.edu/~matchev/talks/Matchev_DPF2011.pdf Matchev_DPF2011_pdf.pdf

5 Beyond the Standard Model: experiment

Speaker: George Redlinger (Brookhaven National Laboratory (BNL))

Slides dpf11.pdf

10:15 AM Coffee

Plenary Session

Convener: Kate Scholberg (Duke University)

6 Neutrino Physics: theory

Speaker: Prof. Lisa Everett Everett (University of Wisconsin)

Slides dpf2011_everett.pdf

7 Neutrino Physics: experiment

Speaker: Jennifer Raaf (FNAL)

Slides 2011DPF_NeutrinoExpts_Raaf.pdf

8 Searches for BSM Physics at Low Energy

Speaker: Krishna Kumar (Physics Department University of Massachusetts Amherst)

Slides 35_KrishnaKumar.pdf

Forum on Physics and Modern Media

9 Panel Discussion

Chair - Ken Bloom (Nebraska), Gordon Watts (UW Seattle)

Speakers: Adrian Cho, Lisa Van Pay, Michael Henry Schmitt (Department of Physics and Astronomy)

Slides APS_DPF_Cho.pdf APS_DPF_Cho.ppt

12:30 PM Lunch

Poster Session

The posters will be displayed until Friday 14:00

Conveners: Greg Landsberg (Brown University), Meenakshi Narain (Brown University), Ulrich Heintz (Department of Physics-Brown University)

10 Are Leptons and Quarks Highly Relativistic Bound States?

Because the existence of families of elements and hadrons was ultimately understood by the realization that atoms and hadrons are composite, in the 1970's many physicists thought that the existence of the four families of leptons and quarks could be understood if leptons and quarks were composite. By the early 1980's, however, the physics community had given up on the idea because it had not been possible to determine the force that binds constituents into leptons and quarks. The development of supercomputers now makes it feasible to study such highly relativistic bound states. Here the possibility is discussed that leptons and quarks are highly relativistic bound states of a scalar and spin-1/2 fermion bound by minimal electrodynamics. These bound states are described by the Bethe-Salpeter equation and have the following three properties, all of which are essential if quarks and leptons are composite: (1) The boundary conditions allow strongly bound solutions when the coupling constant has a magnitude on the order of the fine structure constant. Typically the coupling constant for strongly bound solutions is on the order of or greater than unity. (2) All strongly bound, normalizable solutions must have spin-1/2 if the coupling constant has a magnitude on the order of the fine structure constant. It is remarkable that higher spin, strongly bound solutions are forbidden. (3) Some strongly bound solutions possess a property that suppresses the unobserved decay of a muon into an electron and a photon.

Speaker: G. Bruce Mainland (The Ohio State University at Newark)

11 Interparticle forces in scalar QFTs with non-linear mediating fields

We study the interparticle potentials for few-particle systems in a scalar theory with a non-linear mediating field of the Higgs type. We use the variational method, in a reformulated Hamiltonian formalism of QFT, to derive relativistic three and four particle wave equations for stationary states of these systems. We show that the cubic and quartic non-linear terms modify the attractive Yukawa potentials, which are dominant at small interparticle distances, by new terms that produce confining and quasi-confining interparticle potentials.

Speaker: Mr Alexander Chigodaev (York University)

12 Complex Path Integral as a Fractional Fourier Transform

Lately, it is becoming increasingly clear that extending the Feynman Path Integral into the Complex domain yields desirable properties. A first hint in support of such construction can be seen from the connection between SUSY Quantum Mechanics and the Langevin dynamics: analytically continuing the Langevin leads into different SUSY Quantum Mechanical systems (which share the same algebra of observables). Secondly, new results by E. Witten have brought forward new results in 3-dimensional Chern-Simons theory (in the form of Complex geometries) and Super Yang-Mills theory in four dimensions, as well as the relation between Khovanov homology and systems of branes. Given a system of D0-branes, it is possible to understand it in terms of a Fourier Transform. As such, we can extend this system into the Complex plane, reinterpreting the Path Integral as a Fourier Transform over a certain integration cycle, which results in a Fractional Fourier Transform. This can be further understood in terms of the Phase Space of this system, where the Fractional Fourier Transform is related to the Wigner function. In this way, we realize that the label of our Fractional Fourier Transform, which is the Path Integral quantizing the system, acts as the parameter determining the vacuum state. Therefore, the allowed values of this label, for which the Path Integral converges, determine the quantum phases of the system. This can be immediately extended to Matrix models and Lie algebra-valued ones (known as Group Field Theory): the same results hold, so long as certain properties of the Action are satisfied, guaranteeing the convergence of the Path Integral. These results can be dimensionally extended to systems of Dp-branes, showing some relations with the Geometric Langlands Duality and Mirror Symmetry. Furthermore, they can also be understood in terms of coherent state quantization, which opens a window into quantum tomography, and quantum chaos.

Speaker: Dr Daniel Ferrante (Brown University)

Slides poster-DPF11.pdf

13 NS5 Branes on the Resolved Cone over $Y^{p,q}$

The AdS/CFT correspondence provides a powerful tool to attack very important questions of strong coupling dynamics using gravitational duals. The Klebanov-Stassler prototype has a large family of duals that contain ${\cal N}=1$ SYM. A new and distinct family of supergravity solutions containing a sector dual to ${\cal N}=1$ SYM might be related to the resolved cone over Einstein-Sasaki spaces. In this work we extend the construction of five brane solutions on the resolved cone over $Y^{p,q}$ spaces by expanding the generalizations of the complex deformations in the context of the warped resolved deformed conifold. This work augments recent work which established the existence of supersymmetric five branes solutions wrapped on two-cycles of the resolved cone over $Y^{p,q}$ in the probe limit. We present an ansatz and the corresponding equations of motion. Here we attempt to solve the field equations and give explicit solutions with the expected properties for theory related to strongly coupled Yang-Mills theories.

Speaker: Catherine Whiting (University of Iowa)

Poster DPFWhiting.pdf

14 The Value of the Newton Gravitation Constant Derived From a Combined Sakharov and Kaluza-Klein Model of Baryo-Genesis and Gravity EM Unification

A model of Sakharov (1967) baryo-genesis where the 5th , compactified, dimension of Kaluza-Klein (1926) theory does ‘double duty’ as the creator of lepton-baryon numbers and creator of separate EM and gravity equations is proposed. The appearance of the compactified dimension breaks the symmetry of the Planckian vacuum, allowing the vacuum quantities hbar, G, and c to generate the particle quantities e, mp and me , which are the charges and masses of the proton and electron respectively. Under this model the lepton-baryon asymmetry is a reflection time-space dimensional asymmetry and the relationship of the hidden dimension size, ( in esu units) ro = e^2/(moc^2) ,where c is the speed of light, where mo=(mpme)^1/2 , to the Planck Length, rp =(Ghbar/c^3)^1/2 : is ln(ro/rp) = (mp/me)^1/2 and mirrors the lepton-baryon separation. Inversion of this formula leads to a highly accurate formula for G, the Newton Gravitaion constant. Improvement of this model to apply corrections near the Planck scale results a formula for G further improvement in accuracy( in esu): G = alpha (e^2/mo^2 )exp( -2((mp/me)^1/2 -.86/(mp/me) …) = 6.6728 x 10^-8 dyn-cm^2-g^-2, where alpha is the fine structure constant. In the GEM theory of long range field unification ( Brandenburg 1988, ,1995, 2010) gravity fields are equivalent to an array of ExB drift cells or Poynting vectors and EM and gravity fields separate with the appearance of the Kaluza-Kline 5th dimension. The predicted hidden dimension size is 3000.0 MeV and lies right between the eta-c and J/psi particles and almost exactly on the Sigma (3000) baryon. Assuming a model where the proton-electron ( lepton-baryon) field unification occurs in a U(1) symmetry with imaginary rotation angle determined by normalized charge q/e and a multiplier ln(s’) where s’ = (mp/me)^1/2 ( the square root of the mass ratio) we obtain approximately, with qP =chbar ( the Planck charge) , we obtain the approximate relation: MP/mp = exp(ln(s’)qP/e) , where MP is the Planck Mass, when combined with the previous relations, we obtain, to leading order, “The Transcendental Cosmos Equation” relating the value of alpha to s': s’ = ln(s’) (1/alpha^1/2 +1) –ln(1/alpha)~42.85...This is similar to the "MIT Bag Model" (Chodos et al. ,1974)result s' ~ (4pi/alpha)^1/2 Humorously, this recalls the number "42" which appeared in Hichhikers Guide to the Galaxy as the " answer to life, the universe, and everything" however, this author makes no such claims. Brandenburg J.E. ( 1988) APS Bull.,33, 1, p.32.Brandenburg, J. E., (1995), Astrophysics and Space Science, 227, pp. 133.Brandenburg J.E. ( 2010) OSAPS Meeting .Chodos, R. L. Jaffe, K. Johnson, and C. B. Thorn,(1974) Phys. Rev. D 10, 2599 Klein, Oskar Zeitschrift fur Physik, 37, 895, (1926).Sakharov A.D. JETP 5,24-27, (1967).

Speaker: Dr john brandenburg (Orbital Technologies Corporation)

15 Theory of EW interactions with dynamically generated scalars, gauge fixings, and masses of Z and W bosons

A new theory of the EW interactions without spontaneous symmetry breaking, Higgs, and Fadeev-Popov procedure is presented in this talk. It consists of three parts: $SU(2)_L\times U(1)$ gauge fields, massive fermion fields, and their interactions. New mechanism of $SU(2)_L\times U(1)$ symmetry breaking caused by the fermion masses are found. Nonperturbative solutions are found. The vacuum polarization of the Z field is expressed as \[\Pi_{\mu\nu}(q^2)=\{F_1(q^2)(q_\mu q_\nu-q^2 g_{\mu\nu})+F_2(q^2)q_\mu q_\nu+{1\over2}\Delta m^2_Z g_{\mu\nu}\}.\] Therefore, both the gauge fixing term($F_2$) and the mass term of the field are dynamically generated from the fermion masses. Top quark mass plays a dominant role. No zero $\partial_\mu Z^\mu$ leads to a scalar field and a gauge fixing term for the Z field. The mass of the scalar field is determined to be \[m_{\phi^0}=m_t e^{\frac{m^2_Z}{m^2_t}\frac{16\pi^2}{3\bar{g}^2}+1}=3.78\times10^{14}GeV.\] The gauge fixing is determined to be \[\xi_z=-1.18\times10^{-25}.\] After renormalization it is determined \[m_z={1\over2}\bar{g}^2 m^2_t\] it agrees well with the data. Similarly, the vacuum polarization of W boson is found. A charge scalar field is dynamically generated \[m_{\phi^{\pm}}=m_t e^{\frac{m^2_W}{m^2_t}\frac{16\pi^2}{3g^2}}=9.31\times10^{13}GeV.\] \[\xi_W=-3.73\times10^{-25}.\] After renormalization the mass of the W boson is determined as \[m^2_W={1\over2}g^2 m^2_t.\] It agrees well with the data. It also obtain \[\frac{m^2_W}{m^2_Z}=\frac{g^2}{\bar{g}^2}=cos^2\theta_W.\] \[G_F=\frac{1}{2\sqrt{2}m^2_t}.\] The Fermi coupling constant in good agreement with data. The propergators of Z- and W- fields are derived as \[\Delta_{\mu\nu}^Z= \frac{1}{q^2-m^2_Z}\{-g_{\mu\nu}+(1+\frac{1}{2\xi_Z})\frac{q_\mu q_\nu}{ q^2-m^2_{\phi^0}}\}\] \[\Delta^W_{\mu\nu}= \frac{1}{q^2-m^2_W}\{-g_{\mu\nu}+(1+\frac{1}{2\xi_W})\frac{q_\mu q_\nu}{ q^2-m^2_{\phi_W}}\}\] This theory can be tested by LHC experiments.

Speaker: Bing An Li (University of Kentucky)

Slides dpf111.pdf

16 On the Smallness of the Dark Energy Density in Split SUSY Models Inspired by Degenerate Vacua

It is well known that in no--scale supergravity global symmetries protect local supersymmetry (SUSY) and a zero value for the cosmological constant. The breakdown of these symmetries that ensures the vanishing of the vacuum energy density near the physical vacuum leads to the natural realization of the multiple point principle (MPP) assumption, i.e. results in the set of degenerate vacua with broken and unbroken local supersymmetry. We present the minimal SUGRA model where the MPP assumption is realised naturally at the tree--level. In this model vacua with broken and unbroken local supersymmetry in the hidden sector (first and second phases) have the same energy density without any extra fine-tuning. Although hidden sector does not give rise to the breakdown of supersymmetry in the second phase SUSY may be broken there dynamically in the observable sector. Then a positive value of the energy density in the second vacuum is induced which can be assigned, by virtue of MPP, to all other phases including the one in which we live. The total vacuum energy density is naturally tiny or zero in this case. If gauge couplings in the physical and second vacua are the same then the dark energy density depends on the SUSY breaking scale in the physical vacuum only. Assuming Split SUSY type spectrum we argue that the observed value of the cosmological constant can be reproduced if the masses of squarks and sleptons are of order of 10^{10} GeV.

Speaker: Dr Roman Nevzorov (University of Hawaii)

Poster cc-dpf-2011.pdf

17 Sticky Dark Matter

There is experimental evidence that Dark Matter (DM) makes up about 25\% of the Universe mass and is most likely non­relativistic. We explore possibility of creation and existence of bound states of Dark Matter and standard model (SM) particles. Such bound states can be potentially created and detected during direct DM search experiments (DAMA, CDMS, XENON etc.). We work in model-­independent effective field theoretic approach to determine conditions under which such bound states can be created. Our results appear to be dependent on nuclei used in DM direct detection experiments. In this scenario we determine the region of DM parameter space that provides simultaneous fit to DAMA and CDMS data.

Speaker: Prof. Alexey Petrov (Wayne State University)

18 Possible Existence of Overlapping Universe and Antiuniverse

The creation of antihydrogens at CERN (1995) and Fermilab (1997) and the very recent synthesizing of antiheliums at CERN (2011) have invigorated the fascinating idea about the existence of separate universe and antiuniverse as a resultant of the big bang. Particularly, the production of exotic atoms composed of particles and antiparticles (e.g. positroniums, Ps, protoniums, Pn, true muoniums, Mu, and pioniums, A2π) as well as the experimental formation of positronium molecules, Ps2, and theoretical predictions of exotic four-body systems composed of matter and antimatter (e.g. Heterohydrogens, PsPn, Ps Mu, PsA2π ) open the gate in front of new research activities aiming to investigate the possible existence of overlapping universe and antiuniverse. The main goal of the present work is to discuss this possibility and show that it provides us with satisfactory explanations of the dilemma connected with the rare existence of antimatter in our universe and the mysterious astrophysical observation of highly energetic gamma-rays occurring at the edge of our universe.

Speaker: Prof. Mohamed Assad Abdel-Raouf (United Arab Emirates Un iversity, College of Science)

19 Strictly Calculate the Electron Mixing-loop Chain Propagator in SM

Employing the electroweak standard model(SM), we analyzed and discussed the framework form of electron mixing-loop chain propagator and its renormalization in detail; then achieved the analytic count. Based on it we acquired the analytic solution of electron mixing-loop chain propagator which composed of serious of different physical loops. This study would offer certain academic reference to the discussion and applying about normal complex propagators in both theoretical analyzing and application.

Speaker: Dr Haiyan Tang (Department of Mathematics and Physics, Chongqing University of Science and Technology, Chongqing, China)

20 Missing Transverse Energy Significance

The missing transverse energy (MET) plays a fundamental role in the search for physics beyond the Standard Model at the LHC. We present an event-by-event assessment, the MET significance, of whether the observed MET is consistent with arising solely from detector-related limitations, such as measurement resolution and detection or reconstruction efficiency. We will introduce the formal definition of the significance, discuss our implementation, and show the results of performance studies of the particle flow MET significance in di-jet and W → e + ν data samples collected with the CMS detector.

Speaker: Dr Dayong Wang (Department of Physics-University of Florida)

Poster MetSigPoster.pdf

21 On a Singular Solution in Higgs Field (2) - A Representation of Certain f0 Mesons' Masses.

In preceding paper 1) the mass and the basic structure of SM Higgs boson (H0) were discussed by obtaining asymptotic solution for the Euler-Lagrange equation of nonlinear Klein-Gordon type, in Higgs field with newly developed mass triangle method. In this paper we at first see that the ground state mass of glueball (GB) is calculated at 502.55 MeV/c2 which is expected as f0(600) meson’s mass. The GBs will attract mutually with neighbors among original their components of gluons in different colors, so that they could gradually form cluster. And we show that our computed masses of f0(1370), f0(1500) and f0(1710) are within each f0 meson’s mass from experiment while they will construct respective fullerene structure for ur-H0 as well as f0(600), provided that the mass of ur-H0 (120.611 GeV/c2) will consist of a number of masses of GB or f0 in which all (pure) GB fullerene may have an icosahedral (Ih) rotational symmetry. Finally we propose a representation by which f0 mesons masses above are reproduced respectively with masses of several light pseudoscalar mesons such as η0, K0, K0_bar, K±, π0, π± and GB, under the consideration of those junction networks. Where the mass of f0(1500) is described only by the mass of GB. And also ur-H0 will transform into H0 under mass invariance through, for instance, γf0 reaction to ηc as its component via radiative decay of J/ψ. Along with these discussions, a massive gluon propagator for virtual top quark-pair decay is calculated by Bethe-Salpeter equation. 1)Kazuyoshi Kitazawa, APS APRIL MEETING 2011, K1.00034.

Speaker: Kazuyoshi Kitazawa (Mitsui Chemicals)

Slides 166_K-Y_Kitazawa.pdf

22 Semi-leptonic D_s^+ (1968) Decays as a Scalar Meson Probe

The unusual multiplet structures associated with the light spin zero mesons have recently attracted a good deal of theoretical attention. Here we present some aspects associated with the possibility of getting new experimental information on this topic from semi-leptonic decays of heavy charged mesons into an isosinglet scalar or pseudoscalar plus leptons.

Speaker: Muhammad Shahid (Syracuse University)

Poster Ds semiletonic decays.pdf

23 Sanford Underground Laboratory at Homestake

The status of the Sanford Underground Laboratory at Homestake in Lead, South Dakota will be presented. Excavation of new underground facilities at 4850 feet (about 1480 m) has been completed. Outfitting of the excavated space to house and support the Large Underground Xenon (LUX) detector searching for dark matter and the MAJORANA DEMONSTRATOR neutrinoless double-beta decay experiment is underway and is anticipated to be complete by early 2012. The capability to produce very low background copper by electroforming for the MAJORANA DEMONSTRATOR experiment is now operational at the 4850-foot level. Experiments associated with research in underground biology and geosciences are underway or planned at the Sanford Laboratory.

Speaker: Dr Jaret Heise (Sanford Underground Laboratory at Homestake)

Poster 537-JaretHeise.pdf

Accelerator Physics

Conveners: R. Joel England (SLAC), Dr Vladimir Shiltsev (Fermilab)

24 Tevatron Accelerator Methods and Techniques Applicable for Future Accelerators

The success of Tevatron Run II is based on advances in accelerator physics, as well as on the excellence and advances in engineering, instrumentation and machine operation. We review the main advances in accelerator physics which contributed to the luminosity growth and/or improvement of the Tevatron complex operations, and discuss their applicability to future colliders.

Speaker: Mr Valeri Lebedev (FNAL)

Slides Tevatron.pdf

25 High-luminosity operation of RHIC and future upgrades

The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory has now operated for a decade. Over this time the 2 physics programs at RHIC, based on heavy ion and polarized proton collisions respectively, have seen a substantial increase in performance and a variety of operating modes. The performance increases are presented with the dominant limiting effects, and upgrade plans for the next decade. The heavy ion luminosity upgrade is primarily based on stochastic cooling in store, and an increase in the longitudinal focusing. A new polarized source is expected to increase both the polarization and luminosity. For the latter electron lenses are also implemented to partially compensate the head-on beam-beam effect. In addition, a number of new operating modes are considered.

Speaker: Dr Wolfram Fischer (BNL)

Slides 2011-0809_DPF2011,_High-luminosity_operation_of_RHIC_and_future_upgrades,_W._Fischer.pdf 2011-0809_DPF2011,_High-luminosity_operation_of_RHIC_and_future_upgrades,_W._Fischer.pptx

26 Status of the Super-B factory Design

The SuperB international team continues to optimize the design of an electron-positron collider, which will allow the enhanced study of the origins of flavor physics. The project combines the best features of a linear collider (high single-collision luminosity) and a storage-ring collider (high repetition rate), bringing together all accelerator physics aspects to make a very high luminosity of 10^36 cm−2 sec−1. This asymmetric-energy collider with a polarized electron beam will produce hundreds of millions of B-mesons at the Υ(4S) resonance. The present design is based on ex- tremely low emittance beams colliding at a large Piwin- ski angle to allow very low βy⋆ without the need for ultra short bunches. Use of crab-waist sextupoles will enhance the luminosity, suppressing dangerous resonances and allowing for a higher beam-beam parameter. The project has flexible beam parameters, improved dynamic aperture, and spin-rotators in the Low Energy Ring for longitudinal po- larization of the electron beam at the Interaction Point. Optimized for best colliding-beam performance, the facility may also provide high-brightness photon beams for synchrotron radiation applications.

Speaker: Dr Walter Wittmer (SLAC)

Slides Status_of_the_Super-B_factory_Design.pdf

Beyond the Standard Model

Convener: Dr Ariel Schwartzman (SLAC)

27 MiniReview of Beyond the Standard Model Physics

Over the last 30 to 40 years the Standard Model has had remarkable agreement with a large variety of experimental tests. With the large accumulated datasets at the Tevatron and the LHC the TeV scale is now being probed in detail. In this talk we will review the state of searches for physics beyond the Standard Model. In particular, we will focus on the recent results from the LHC which significantly expand the limits on many models and discuss a few interesting anomalies which have been observed at the Tevatron.

Speaker: Kevin Black (Department of Physics-Boston University)

Slides DPF11.pdf

28 Search for Heavy Vector-like Quarks at ATLAS in pp Collisions at $\sqrt{s}$=7 TeV

We perform a search for vector-like quarks more massive than the top quark coupling to lighter generations using data collected with the ATLAS detector. The W and Z bosons are reconstructed in the $W\rightarrow l^{\pm}\nu$ and $Z\rightarrow l^{+}l^{-}$ where $l=e,\mu$. The vector-like quark is reconstructed from the W or Z and the highest $p_{T}$ jet.

Speaker: Mr Samuel Meehan (University of Chicago)

Slides 387_SamMeehan.pdf

29 Search for Fourth Generation Quarks at CMS

The Standard Model with three generations of quarks describes remarkably well all particle phenomena observed to date. Although adding a fourth generation of massive fermions is an obvious extension of the model, it became less popular ever since the limit on light neutrino flavors, and the precise measurements on the electroweak parameters, seem to disfavor such a possibility. However, indirect limits can never replace direct search for heavy particles. We present the results of a search for the heavy fourth generation quark using the CMS detector in pp collisions of the Large Hadron Collider.

Speaker: Michael Luk (Brown University)

Slides dpftalk-mmhl-updated030811.pdf

30 Model independent search for new phenomena in ppbar collisions at sqrt(s) = 1.96 TeV

We present a model independent search for physics beyond the standard model in lepton final states. We examine data in 120 unique final states from 1.07 fb-1 of at ppbar collisions at sqrt(s) = 1.96 TeV collected with the D0 detector. We conclude that all discrepancies seen can be attributed to modeling issues and do not claim evidence of new physics.

Speaker: Dr Peter Renkel (postdoc)

Slides DPF2011.pdf

Detector Technology and R&D

Conveners: James Brau (Univ. of Oregon), Maurice Garcia-Sciveres (LBNL)

31 Upgrade plans of the CMS detector

Overview of upgrade plans.

Speaker: Daniela Bortoletto (Purdue)

Slides 431_Bortoletto_CMSdetector_upgrades_v1.pdf 431_Bortoletto_CMSdetector_upgrades_v1.pptx

32 ATLAS detector upgrade plans

Overview of plans for ATLAS detector upgrades up to 2022.

Speaker: Venetios Polychronakos (Department of Physics-Brookhaven National Laboratory (BNL))

Slides DPF_20110809.pdf DPF_20110809.pptx

33 A Fast Hardware Tracker for the ATLAS Trigger System

In hadron collider experiments, triggering the detector to store interesting events for offline analysis is a challenge due to the high rates and multiplicities of particles produced. The LHC will soon operate at a center-of-mass energy of 14 TeV and at high instantaneous luminosities of the order of 10^34 to 10^35 / cm^2 / second. A multi-level trigger strategy is used in ATLAS, with the first level (L1) implemented in hardware and the second and third levels (L2 and EF) implemented in a large computer farm. Maintaining high trigger efficiency for the physics we are most interested in while at the same time suppressing high rate physics from inclusive QCD processes is a difficult but important problem. It is essential that the trigger system be flexible and robust, with sufficient redundancy and operating margin. Providing high quality track reconstruction over the full ATLAS detector by the start of processing at L2 is an important element to achieve these needs. As the instantaneous luminosity increases, the computational load on the L2 system will significantly increase due to the need for more sophisticated algorithms to suppress backgrounds. The Fast Tracker (FTK) is a proposed upgrade to the ATLAS trigger system. It is designed to enable early rejection of background events and thus leave more L2 execution time by moving track reconstruction into a hardware system that takes massively parallel processing to the extreme. The FTK system completes global track reconstruction with near offline resolution shortly after the start of L2 processing by rapidly finding and fitting tracks in the inner detector for events passing L1 using pattern recognition from a large, pre-computed bank of possible hit patterns. We describe the FTK system design and expected performance in the areas of b-tagging, tau-tagging, and lepton isolation which play and important role in the ATLAS physics program.

Speaker: Mark Neubauer (University of Illinois at Urbana-Champaign)

Slides 361_MarkNeubauer.pdf 361_MarkNeubauer.pptx

Electroweak Physics

Conveners: Prof. Doreen Wackeroth (SUNY Buffalo), Prof. Sridhara Dasu (University of Wisconsin)

34 Review of Electroweak Physics at Hadron Colliders

Experiments at the Tevatron and the LHC have recently studied the electroweak gauge sector of the Standard Model with impressive breadth and precision. In this talk we discuss several new experimental results, and the theoretical progress they have spurred.

Speaker: Frank Petriello (Northwestern University)

Slides DPF2011.pdf

35 Measurement of the differential production cross section of Z bosons at 7 TeV

In 2010 the CMS experiment collected about 35 pb-1 of data during the first physics run of the LHC accelerator. We present the first measurements of the differential cross section as a function of boson rapidity and transverse momentum for Z bosons produced at 7 TeV and decaying to pairs of electrons and muons. The data are unfolded and corrected for efficiencies, allowing a direct comparison to recent theoretical calculations.

Speaker: Joseph Anthony Gartner (University of Florida)

Slides gartner_EWK_DPF_Aug2011.pdf

36 Measurement of the Drell-Yan differential cross section at 7 TeV

We present a measurement of the Drell-Yan differential cross section in pp collisions as a function of the dilepton invariant mass (dsigma/dm). The data sample was collected by the CMS detector at the LHC operating at a center-of-mass energy of 7 TeV during 2010 and 2011. The results are compared to predictions of the Standard Model.

Speaker: Stoyan Emilov Stoynev (Department of Physics and Astronomy-Northwesten University)

Slides DY_CMS_DPF_09.08.11_v3.pdf

37 W and Z production in the forward region with the LHCb experiment

Results are presented of W and Z boson production in pp collisions at $\sqrt(s)=7$ TeV by the LHCb experiment. These studies are of particular interest due to LHCb's unique forward acceptance in pseudo-rapidity ($\eta$) of 2 $< \eta <$ 5. The results may either be interpreted as a test of Standard Model predictions, or may be used to constrain better parton density functions in this kinematical regime.

Speaker: Jonathan Anderson (Universitaet Zuerich)

Slides DPF_Anderson.pdf

Heavy Flavor Physics: Quarkonium

38 Studies with onia at LHCb

LHCb results will be presented of studies made of the production of $c\bar{c}$ and $b\bar{b}$ states in $pp$ collisions at $\sqrt{s} = 7$~TeV. The range and precision of these measurements will be invaluable in discriminating between theoretical models. Results and prospects will also be shown for so-called exotics, such as the X(3872).

Speaker: Luigi Li Gioi (Lab. de Physique Corpusculaire (LPC)-Inst. Nat. Phys. Nucl. et)

Slides 10_LuigiLiGioi.pdf

39 Measurement of Quarkonia production at 7 TeV with the CMS experiment

The measurement of J/psi and Υ production cross section in proton-proton collisions at √s = 7 TeV is presented using a data sample collected with the CMS detector at the LHC. We also report the measurement of the ratio of X(3872) and psi(2S) signal yields.

Speaker: Yu Zheng (Purdue University)

Slides dpf_quarkonia_Yu.pdf

40 New Measurements of Production and Polarization of Heavy Mesons at CDF

We present a new measurement of the Upsilon(1S), (2S), and (3S) polarization in dimuon events from p-pbar collisions at 1.96 TeV, using the CDF detector at the Tevatron. The measurement is conducted exploiting the full 3-dimensional angular distributions over a pT range of 2-40 GeV/c, based on data comprising an integrated luminosity of 6.0 fb-1. We also report the first measurement of production cross-section of low-pt D0 mesons at the Tevatron..

Speaker: Niharika Ranjan (Purdue University)

Slides http://www.physics.purdue.edu/~nranjan/dpf2011/dpf.pdf

Heavy Ion Physics/Hot and Dense QCD

Conveners: Derek Teaney (Stony Brook University), Prof. Olga Evdokimov (UIC)

41 Deconfinement and chiral transition in QCD at finite temperature

I am going to discuss new lattice results on the deconfinement and chiral aspects of the transition in QCD at non-zero temperature. I will report on calculations performed using the Improved Staggered Quark action on Nt=6, 8 and 12 lattices. I will show continuum extrapolation for several quantities that are discussed in connection with the transition at non-zero temperature as well as the determination of the chiral transition temperature in the continuum limit. Finally I will discuss new findings for the equation of state.

Speaker: Peter Petreczky (BNL)

Slides dpf2011.pdf dpf2011.ppt

42 QCD Critical Point and Event-by-event Fluctuations

QCD critical point is a singularity on the QCD phase diagram with distinct signatures which make possible its discovery in heavy-ion collisions. I shall describe the characteristics of the non-monotonous behavior of observables measuring the magnitude and non-Gaussianity of event-by-event fluctuations as a function of the beam energy in the presence of the QCD critical point. I shall discuss implications for the RHIC Beam Energy Scan and what we can learn from recent data.

Speaker: Prof. Misha Stephanov (UIC)

Slides dpf-2011-slides.pdf

43 Identified Hadron Production from the RHIC Beam Energy Scan Program in the STAR experiment

The current focus at RHIC is the Beam Energy Scan (BES) program to study the QCD phase diagram --- temperature ($T$) vs. baryon chemical potential ($\mu_B$). The BES program aims to verify some predictions from QCD: that a cross-over occurs at $\mu_B$ = 0, and that there exists a first-order phase transition at large $\mu_B$ and a critical point at an intermediate $\mu_B$. The spectra and ratios of produced particles can be used to extract $T$ and $\mu_B$ in different energies and system sizes. The Solenoidal Tracker At RHIC (STAR) experiment has collected data for Au+Au collisions at $\sqrt{s_{NN}}=$ 7.7 GeV, 11.5 GeV, and 39 GeV in year 2010. One of the advantages during the BES program was the enhanced particle identification with availability of full Time-Of-Flight detector. In addition, STAR collected Cu+Cu collisions at 22.4 GeV in year 2005. We present mid-rapidity spectra ($p_{T}$ or $m_{T}-m_{0}$), rapidity density, average transverse mass, and particle ratios for identified hadrons from the STAR experiment. The centrality and transverse momentum dependence of the particle yields and ratios will be compared to existing data at lower and higher beam energies and to various transport models like AMPT and UrQMD. Collision dynamics are studied systematically in the framework of chemical and kinetic freeze-out and their properties extracted from the particle ratios and spectra.

Speaker: Dr lokesh kumar (Kent State University)

Slides Lokesh_DPF_Brown.pdf

44 Recent Results of Fluctuation and Correlation Studies from the QCD Critical Point Search at RHIC

Enhanced fluctuations and correlations have been observed in the phase transitions of many systems. Their appearance at the predicted QCD phase transition (especially near the expected critical point) may provide insight into the nature of the phase transition. Recent results from the QCD Critical Point Search at RHIC will be presented, with a focus on particle ratio (K/$\pi$, p/$\pi$, and $K/p$) fluctuations and their comparison to previous measurements and theoretical predictions.

Speaker: Dr Terence John Tarnowsky (Michigan State University)

Slides DPF_Aug_2011.pdf

Higgs Physics

Conveners: Dr Laura Reina (Florida State University), Prof. Wade Cameron Fisher (Michigan State University)

45 Search for the Standard Model Higgs boson in H->ZZ decay channels with the ATLAS detector

The SM Higgs boson in the medium and high mass ranges has a large branching ratio for decays to a pair of neutral weak bosons. Three decay modes of the Z boson pair have been explored by ATLAS. One Z is typically produced on-shell, which can be tagged using leptonic decay products. The decay of the second Z(*) leads to three independent search channels: llqq, llvv and llll. Background compositions and topologies differ among these channels. The llqq search can use jet information to reduce top and Z+jets backgrounds; the llvv search requires a good understanding of missing transverse energy, while the 4 lepton ('golden') channel is almost background-free and, owing to its low production rate, needs excellent lepton efficiencies in order to be sensitive. This talk summarizes results in all three H->ZZ channels using data collected in 2011.

Speaker: G Carrillo Montoya (Department of Physics-University of Wisconsin)

Slides GD_CARRILLOMONTOYA_HZZ.pdf GD_CARRILLOMONTOYA_HZZ.pptx

46 Search for the Higgs boson in leptonic ZZ* and semileptonic WW* decays in proton-antiproton collisions at 1.96 TeV

We present a search for the Standard Model Higgs boson produced via the H->WW*->lvjj and H->ZZ*->4l processes at a center-of-mass energy of 1.96 TeV using up to 8.5 fb-1 of data collected with the D0 and CDF detectors at the Fermilab Tevatron collider. We search in events with either four charged leptons, or two jets, one charged lepton, and missing transverse energy. The four lepton channel provides a very clean signature, although at the expense of a low cross section time branching ratio. The semi-leptonic H->WW* channel has a relatively larger cross section times branching ratio, but is overcome by the large W+jets background. The procedures used to perform these searches will be discussed.

Speaker: Savanna Shaw (MIchigan State University)

Slides HWWlnujj_H4l_DPF2011.pdf

47 A Search For The Higgs Boson In H --> ZZ --> 2l 2jet Mode

We report on a search for SM Higgs Boson in the mode H --> ZZ--> 2l 2jet conducted by the CMS experiment with the data accumulated during the 2010 & 2011 running of the LHC at sqrt(s) = 7 TeV.

Speaker: Ashish Kumar (Department of Physics-Physics Faculty-State University of New Y)

Slides DPF11_H_ZZ_lljj.pdf

48 A Search For The Higgs Boson In H --> ZZ--> 4l Mode

We report on a search for SM Higgs Boson in the mode H --> ZZ--> 4l conducted by the CMS experiment with the data accumulated during the 2010 & 2011 running of the LHC at sqrt(s) = 7 TeV.

Speaker: Mario Pelliccioni (Universita degli Studi di Torino-Universita e INFN)

Slides dpf2011_hzz4l.pdf

Low Energy Searches for Physics Beyond the Standard Model

Conveners: Shufang Su (University of Arisona), William Molzon (University of California, Irvine)

49 Search for a Neutron Electric Dipole Moment at the Paul Scherrer Institut

At the new ultracold neutron source at the Paul Scherrer Institut(PSI) a collaboration of 15 European institutions is setting up an experiment to search for the nEDM with improved sensitivity. The same apparatus which provided the present best limit on the nEDM (d < 2.9 x 10-26 ecm 90% CL, Baker et al., Phys. Rev. Lett. 97 (2006) 131801), was moved from the Institut Laue Langevin (ILL) in spring 2009 to PSI. Since then it was thoroughly investigated and several components have been upgraded and improved. Most remarkable are: the HV system, the magnetic field control and demagnetization method, the mercury co-magnetometer, and an additional 12 channel array of scalar cesium magnetometers. In December 2010 we could store first UCN in our apparatus at PSI. This spring the co-magnetometer was running continuously during several weeks for a measurement of the mercury geometric phase, one of the most important systematic effects. In general all subsystems are working. We have ongoing studies improving the understanding of systematic effects. First data taking runs are scheduled for autumn 2011. Expected statistics might be sufficient to improve on the previous result. Two hundred nights of data taking in 2012 and 2013 should increase the sensitivity to dn < 5×10-27 ecm in the case of a null result. Simultaneously the collaboration is developing an entire new apparatus to further gain an order of magnitude in sensitivity O(10-28) from 2015 onwards.

Speaker: Dr Philipp Schmidt-Wellenburg (Paul Scherrer Institut)

Slides 20110805_nEDM_PSI_PSchmidt-Wellenburg.pdf 20110805_nEDM_PSI_PSchmidt-Wellenburg.ppt

50 A Search for the Electric Dipole Moment of the Neutron

The experimental search for a neutron electric dipole moment could reveal new sources of time-reversal (T) and charge-conservation-and-parity (CP) violation and challenge proposed extensions to the Standard Model. The goal of the present experiment is to improve the measurement sensitivity of the neutron EDM by two orders of magnitude. The physics goals of this experiment remain timely and of unquestioned importance. There is ample reason to expect a nonzero value for the neutron EDM: many theories predict EDM values within the six orders-of-magnitude window between the current limit and the value allowed by the Standard Model. The results of this experiment could make a significant complementary contribution to the search for new physics at the Large Hadron Collider (LHC). The experiment is based on the magnetic-resonance technique of rotating a magnetic dipole in a magnetic field. Polarized neutrons and polarized 3He atoms are confined in a bath of superfluid 4He at a temperature of 450 mK. When placed in an external magnetic field, both the neutron and 3He magnetic dipoles precess in the plane perpendicular to the magnetic field. The neutron EDM is determined from the difference in the precession frequencies of the neutrons and the 3He atoms when a strong electric field is applied either parallel or anti-parallel to the magnetic field. The 3He serves as a volume comagnetometer to minimize magnetic-field systematic effects. Due to shielding effects, 3He should have a negligible electric dipole moment. Improvements over previous experiments arise from an increased electric field due to the excellent dielectric properties of superfluid 4He, an increase in the total number of ultracold neutrons (UCNs) stored, and an increased measurement time due to the longer storage of UCN in the cryogenic container. I will review the present status of the construction of the nEDM experiment and outline its role within the context of the international efforts to measure electric dipole moments.

Speaker: Prof. Paul Huffman (North Carolina State University)

Slides 2011_DPF_-_Huffman.pdf

51 EDMs and their implications

The Electric Dipole Moments (EDMs) provide an unique way of probing CP violations. The search for neutron and atom EDMs has reached very high precision after many decades of effort. I will discuss the implications of the EDM search on the theory of SM, SUSY, as well as the Baryogenesis scenarios. In particular, based on the study of the interplay of EDMs and electroweak Baryogenesis in MSSM, we learn that the wino-driven scenario has been ruled out by current EDM bounds, and the bino-driven scenario is the only viable scenario. With the next generation of EDM experiments that are projected to push the sensitivity by another 2 to 3 orders of magnitude, the parameter space of the bino-driven scenario can also be fully covered.

Speaker: Dr Yingchuan Li (Brookhaven National Lab)

Slides EDMatDPF2011.ppt

52 A proton EDM experiment: most sensitive to CP-violation beyond the SM

High intensity polarized proton beams in storage rings make possible the development of an experiment to probe the proton electric dipole moment (EDM) with sensitivity of 10^-29 e-cm. At this level it will be sensitive to new physics at the 3000 TeV and if new physics exists at the LHC scale, it will be sensitive at the sub-micro-radian level of CP-violating phases. The method utilizes an electric storage ring and polarized protons at their magic momentum (0.7 GeV/c) and takes advantage of several years of experience manipulating polarized beams in storage rings. The experimental concepts were scrutinized in two separate and very successful technical reviews, one in December 2009 and one in March 2011. The collaboration is expecting to submit the proton EDM proposal to DOE by the end of June 2011 for CD0.

Speaker: Dr Yannis Semertzidis (BNL)

Slides YkS_DPF_20110809.pptx

Neutrino Physics: Chaired by Jon Urheim

Conveners: , Sam Zeller (FNAL)

53 Solar and Atmospheric Neutrino Physics with Super-Kamiokande

We present neutrino oscillation results based on data samples from all four phases of the experiment (SK-1 through SK-4) over a 15 year running period. Atmospheric neutrino data spanning 5 orders of magnitude in neutrino energy and 4 orders of magnitude in baseline are used to constrain the mixing parameters of neutrino oscillation as well as search for non-standard effects. Solar neutrino data is also used to constrain mixing parameters and search for evidence of day night differences and spectral distortion.

Speaker: Roger Wendell (Duke University)

Slides wendell_skatm_201108.pdf

54 Low Energy Neutrino Astronomy in Super-Kamiokande

Super-Kamiokande is sensitive to neutrino interactions between 4 and 100MeV via elastic scattering and inverse beta decay. I will present Super-Kamiokande's ongoing measurements of solar neutrinos and its searches for supernova neutrinos.

Speaker: Dr Michael Smy (UCI)

Slides dpf2011_smy_sklowe.pdf dpf2011_smy_sklowe.ppt

55 MINOS Electron-neutrino Appearance Analysis

MINOS is a long-baseline neutrino oscillation experiment which started commissioning in 2005. MINOS has provided many physics opportunities in the past few years. It has made best measurement of $\Delta m^{2}_{32}$ and made the first measurement of $\Delta \bar{m}^{2}_{32}$. MINOS also set the most stringent limit to the fraction of active neutrinos transition to sterile neutrinos. MINOS made attempts to measure $\theta_{13}$ and has obtained comparable limit with the current best limit depending on the CP-violation phase and the neutrino mass hierarchy. With more data and improved analysis technique, MINOS might also set better limit to $\theta_{13}$ within this year. Since MINOS will end soon, MINOS+ has been proposed to run the experiment at high energy mode.

Speaker: Dr Xiaobo Huang (Argonne National Laboratory)

Slides MINOS-overview.pdf

56 Search for Electron Neutrino Appearance in MINOS

The MINOS Collaboration continues its search for electron neutrino appearance in the NuMI beam at Fermilab. Neutrinos in the beam interact in the Near Detector, located 1 km from the beam source, allowing us to characterize the backgrounds present in our analysis. In particular, we can estimate the number of electron neutrino candidate events we expect to see in the Far Detector (735 km away, in the Soudan mine in northern Minnesota) in the presence or absence of muon neutrino to electron neutrino oscillation. Recent efforts to improve the sensitivity of the analysis, including upgrades to the event identification algorithm and fitting procedure, are discussed, and the latest results from the search are presented.

Speaker: Mr Mhair Orchanian (Caltech)

Slides 193_MhairOrchanian.pptx

57 Electron Antineutrino Appearance in MINOS

The Main Injector Neutrino Oscillation Search (MINOS) is a long-baseline neutrino experiment that utilizes Fermilab’s NuMI beam and two steel-scintillator calorimeters. Designed to search for νµ disappearance, MINOS provides an opportunity to study νe appearance as well. Analysis methods developed by the MINOS νe group have facilitated the placement of limits upon the mixing angle associated with νµ to νe oscillations. In addition, the experiment is capable of repeating its analyses using an antineutrino beam. Recent observations of anti-νµ disappearance have motivated supplementary data collection with the antineutrino beam configuration. The benefits of an anti-νe appearance study and MINOS’s anti-νe sensitivity will be presented.

Speaker: Mr Adam Schreckenberger (University of Minnesota)

Slides DPF11v5.pptx

Perturbative and non-Perturbative QCD

Conveners: Christina Mesropian (The Rockefeller University), Sean Fleming (University of Arizona)

58 Mini-Review: Unravelling Jets at Colliders

Jets play an important role in a broad range of collider studies and there have been many recent developments in understanding them. Unravelling their structure enhances our ability to interpret data, search for new physics and develop our understanding of Monte Carlos. This talk reviews some theoretical developments in jet physics and their connection to recent experimental results.

Speaker: Dr Saba Zuberi (UC Berkeley)

Slides 506_SabaZuberi.pdf

59 Jet substructure and event shapes at high Q^2 in ATLAS

We present results on the measurement of hadronic jet event shapes and jet substructure in proton-proton collisions at sqrt(s) = 7 TeV with the ATLAS detector. These measurements constitute the first dedicated study of hadronic event shapes at high Q^2 in ATLAS. New results are also presented on the measurement of the substructure of these jets and in commissioning the tools for distinguishing the signatures of new boosted massive particles in the hadronic final state. Two ``fat'' jet algorithms are used, along with the filtering jet grooming technique that was pioneered in ATLAS. New jet substructure observables are compared for the first time to data at the LHC. Finally, a sample of candidate boosted top quark events collected in the 2010 data is analyzed in detail for the jet substructure properties of hadronic ``top-jets'' in the final state. Together, these measurements demonstrate not only our excellent understanding of QCD in a new energy regime but open the path to using complex event-level and jet substructure observables in the search for new physics.

Speaker: David Miller (SLAC National Accelerator Laboratory)

Slides Miller_JetSubstructure_DPF2011.pdf

60 A New Formulation of Analytic, Non-Perturbative, Gauge-and Lorentz-Invariant QCD

A simple and previously overlooked choice of one parameter allows the Schwinger/Symanzik Generating Functional of QCD to be re-written in a manifestly gauge-invariant fashion, without the need of Fadeev-Popov insertions. When combined with Fradkin functional representations for the Green's function, G[A], of a quark in an effective color potential A, and the vacuum loop functional L[A], all QCD correlation functions can be represented as Gaussian, functional-linkage operations connecting relevant combinations of G[A] and L[A]. And because the Fradkin representations for those functionals are Gaussian in their dependence on A, the functional-linkage operation can be done exactly, and one then sees that gauge invariance here is achieved by gauge-independence, as the gauge-dependent gluon propagators exactly cancel out everywhere. In this way, the non-perturbative sums over Feynman graphs reduce to an explicit, gauge-independent functional expression. That new, final functional expression now displays a new property we call "Effective Locality" (EL), in which the infinite sum over infinite classes of Feynman graphs corresponds to the exchange of a well-defined "gluon bundle" from specific space-time points on interacting quarks and/or antiquarks. And one then sees that it is no longer possible to continue to treat quarks as ordinary particles, with well defined asymptotic momenta or positions, for they are bound objects whose transverse coordinates can never be measured exactly. Once this necessity of introducing realistic "transverse imprecision" is realized, and introduced into the fundamental Lagrangian, all functional sums become well-defined, and one has an analytic way of obtaining physical information. It should be noted that such progress is possible because the Fradkin representations are Potential Theory constructs, with reasonable approximations in different physical situations; e.g., at high energies, G[A] simplifies to a Bloch-Nordsieck/eikonal form. With those simplifications, and the remarkable property of EL, we have been able to calculate eikonal amplitudes for quark-antiquark scattering, and for three-quark scattering, and to extract from these eikonal functions the form of binding potentials that produce hadrons. And, most interesting, for the first time we can exhibit a mechanism which leads to effective Yukawa scattering between nucleons, including a scattering potential which becomes negative, as needed to make a deuteron from a proton and a neutron. This, to our knowledge, and for the first time ever, is Nuclear Physics from basic, realistic QCD. This work, by myself (HMF), French colleagues Grandou and Gabellini (of the Universite de Nice), and my ex-Brown student Ming Sheu, is barely 18 months old at this writing; and there are many problems remaining to be studied, such as non-perturbative renormalization theory, the quark-gluon plasma, and - indeed - all of Nuclear Physics. On the basis of what we have been able to derive up to this point, we believe that this approach to analytic QCD calculations will, in the future, become extremely useful. It should be noted that the above remarks are a description of "textbook" QCD, with one type of quark and the massless gluons of SU(3); flavors and electroweak effects, as well as spin and angular momentum dependences are to be added in later on.

Speaker: Herbert Fried (Brown University)

Slides Fried.pdf

61 The Rapidity Renormalization Group

We introduce a systematic approach for the resummation of perturbative series which involve large logarithms not only due to large invariant mass ratios but large rapidities as well. Series of this form can appear in a variety of gauge theory observables. The formalism is utilized to calculate the jet broadening event shape and and transverse momentum ($p_T$) distributions in a systematic fashion to next to leading logarithmic order. An operator definition of the factorized cross section as well as a closed form of the next-to leading log cross section are presented.

Speaker: Dr Jui-Yu Chiu (Carnegie Mellon University)

Slides Chiu_RapidityRG.pdf

Top Quark Physics: Chaired by Zack Sullivan

Conveners: Reinhard Schwienhorst (Michigan State University), Dr Zack Sullivan (Argonne National Laboratory)

62 Mini-review of the top quark physics

I will present a theoretical overview of the top quark physics. I will discuss the status of theoretical description of various processes at hadron colliders that are used to extract the information about dynamics of top quarks, and their quantum numbers such mass, spin and charge.

Speaker: Kirill Melnikov (Johns Hopkins University)

Slides melnikov_dpf_top.pdf

63 Measurements of the top production cross section and properties with the D0 detector

We present measurements of the inclusive top quark pair production cross section in ppbar collisions at sqrt(s)=1.96 TeV utilizing data corresponding to an integrated luminosity of 5.3 fb-1 collected with the D0 detector at the Fermilab Tevatron collider. We both final states with one charged lepton, at least two jets and missing transverse energy, or final states with two charged leptons, at least one jet and missing transverse energy. We exploit both the kinematic features of the final states and the identification of jets originating from b-quarks to separate the ttbar production signal from backgrounds and obtain measurements of the cross sections which agree with the predictions of the standard model. We then investigate the ttbar final state and obtain a measurement of the top quark branching fractions into b-quarks. Finally we use the sample of ttbar events to investiage the color representation of the hadronically decaying W boson in the ttbar events, using a new calorimeter-based vectorial variable, the "jet pull", sensitive to the color-flow structure of the final state.

Speaker: Liang Li (University of California Riverside)

Slides DPF2011_TopProduction.pdf

64 Top quark physics results using CMS data at 7 TeV

We give an overview of the most recent results on top quark properties and interactions, obtained using data collected with the CMS experiment during the years 2010-2011 at 7 TeV center-of-mass energy. Measurements are presented for both the inclusive top pair production cross section, using the dilepton, lepton+jets, hadronic and tau channels, as well as for various differential cross sections. The results are compared with standard model predictions and allow to search for possible presence of new physics. In particular, measurements of the top pair invariant mass distribution are used to search for new particles decaying to top pairs. We extract the mass of the top quark using various methods, including indirect constraints from the measured cross section. We measure total and differential cross sections for the electroweak production of single top quarks in both t- and tW-channels, also useful for constraining the CKM matrix element Vtb. Further results include measurements of the W helicity in top decays and the top pair charge asymmetry.

Speaker: Prof. Karl Ecklund (Rice University)

Slides Ecklund_CMS_Top_Results.pdf

65 Measurement of the top-pair production cross-section at ATLAS

We present measurements of the top-quark pair-production cross section in proton-proton collisions at sqrt(s) = 7 TeV with the ATLAS detector at the Large Hadron Collider. The cross sections are measured in the lepton+jets channels.

Speaker: Dr M Saleem (University of Oklahoma, USA)

Slides DPF2011-AUG08-16-V04.pdf

3:30 PM Coffee Break

Accelerator Physics

Conveners: R. Joel England (SLAC), Dr Vladimir Shiltsev (Fermilab)

66 Experimental program at Accelerator Test Facility

Few representative experimental results from a 20 year old history of the dedicated advanced accelerator R&D user facility will start the presentation. Evolution of the facility, its current capabilities and experimental program will be discussed in details. Monoenergetic Ion beam generation in laser plasma interaction and observation of Coherent Synchrotron Radiation suppression with shielding plates in the bending magnet will be used to illustrate recent results at ATF. Experimental plans and future upgrades will be also discussed.

Speaker: Dr vitaly yakimenko (bnl)

Slides APS.ppt.pdf

67 Do optical-scale structures make suitable accelerators for colliders?

Of the various advanced accelerator schemes that promise high accelerating gradients, optical-scale structures offer a distinct set of performance parameters along with their own challenges. In addition to the promise of an order of magnitude improvement in accelerating gradients (to ~GV/m) over conventional structures, these devices produce low charge, femto- to atto-second bunches at very high repetition rates (MHz-GHz). The implications for colliders are significant: beam disruption and background beamstraulung might be significantly reduced, but the bunch format may require changes in detectors and trigger systems. Some variants of the optical-scale structures can support flat (high-aspect ratio) beams, which may also be advantageous in a collider. In order to realized such a collider, these devices must demonstrate very high wall-plug efficiency, high reliability and long lifetimes. In this talk, I will attempt to answer the question posed in the title. I will review the present start-of-the-art in optical-scale structures and speculate on the mid- and long-term challenges to be overcome in order to prove their applicability to high-energy physics.

Speaker: Dr Gil Travish (UCLA)

Slides travish_DPF_2011_v3.pdf

68 New Methods of Particle Collimation in Colliders

The hollow electron beam collimator is a novel concept of controlled halo removal for intense high-energy beams in storage rings and colliders. It is based on the interaction of the circulating beam with a 5-keV, magnetically confined, pulsed hollow electron beam in a 2-m-long section of the ring. The electrons enclose the circulating beam, kicking halo particles transversely and leaving the beam core unperturbed. By acting as a tunable diffusion enhancer and not as a hard aperture limitation, the hollow electron beam collimator extends conventional collimation systems beyond the intensity limits imposed by tolerable losses. The concept was tested experimentally at the Fermilab Tevatron proton-antiproton collider. Results on the collimation of 980-GeV antiprotons are presented.

Speaker: Giulio Stancari (Fermi National Accelerator Laboratory)

Slides 421_GiulioStancari.pdf

69 Novel Beam Diagnostics for Future HEP facilities

To meet the energy and luminosity requirements of future HEP machines, advances are required in accelerator instrumentation and technology in many diverse areas, such as: acceleration, component alignment and stability, fast timing instrumentation and optics, photocathodes, pulsed power components, photon detectors, halo monitors, collimators, lasers, insertion devices, noninvasive profile monitors, high resolution position monitors, trapped ion diagnostics, and feedback systems. We will discuss the prospects for these advanced diagnostic techniques with an emphasis on high impact technologies that can significantly enhance the performance and scientific output of future machines.

Speaker: Dr John Byrd (LBNL)

Slides NovelInstJByrdDPF2011.pptx

Beyond the Standard Model

Convener: Dr Ariel Schwartzman (SLAC)

70 Searches for Supersymmetry in Hadronic Final States with the CMS Detector at the LHC

We present the results of searches for Supersymmetry in all-hadronic final states with jets and missing transverse energy, including the cases of jets identified as b-jets, the decay products of top quarks and hadronically decaying tau leptons. The searches are performed using data collected by the CMS experiment at the LHC in pp-collisions at a center-of-mass energy of 7 TeV. Various data-driven techniques used to measure the Standard Model backgrounds are discussed. The results are interpreted in a range of Supersymmetric scenarios.

Speaker: Sudarshan Paramesvaran (University of California Riverside)

Slides DPFSUSY2011Final.pdf

71 Search for supersymmetry in final state containing isolated electrons and muons, jets, and missing transverse momentum from sqrt(s)=7 TeV proton-proton collisions at the LHC

We report on searches for supersymmetry in events with one, two or multi-lepton final states with the 2011 data from the ATLAS experiment. In case of no excess observed a 95% CL upper limit is set for squark and gluino masses for different signal models. A 95% CL limit on the cross section times branching ratios times efficiency is set for different final states under study.

Speaker: Tapas Sarangi (University of Wisconsin)

Slides susy_talk_dpf_2011_TapasSarangi.pdf

72 Searches for Supersymmetry in Final States with Leptons with the CMS detector at the LHC

We present the results of searches for Supersymmetry in various topologies that lead to one or more isolated leptons, jets, and missing transverse energy in the final state. The searches are performed using data collected by the CMS experiment at the LHC in pp-collisions at a center-of-mass energy of 7 TeV. Various data-driven techniques used to measure the Standard Model backgrounds are discussed. The results are interpreted in a range of Supersymmetric scenarios.

Speaker: Benjamin Henry Hooberman (Fermi National Accelerator Lab. (Fermilab))

Slides dpf2011_hooberman_final.pdf

73 Search for Physics Beyond the Standard Model in Opposite-Sign Dilepton Events at CMS

The results of searches for Supersymmetry in events with two opposite-sign isolated leptons, hadronic jets, and missing transverse energy in the final state are presented. The searches use pp collisions at 7 TeV collected in 2011 by the CMS experiment.

Speaker: Derek Michael Barge (Physics Department-Univ. of California Santa Barbara)

Slides dpf2011_v2.pdf

74 Search for New Physics in pp Collisions at √s = 7 TeV in Final States with Missing Transverse Energy and Heavy Flavor

Results are presented of a search for new physics in events with large missing transverse energy and heavy flavor jet candidates in √s=7 TeV proton-proton collisions with the ATLAS detector at the Large Hadron Collider. Several signal regions corresponding to different regions of phase space are examined. The results are interpreted in the context of phenomenological simplified new physics models as well as universal new physics models such as mSUGRA.

Speaker: Bart Butler (SLAC)

Slides 8-9-2011_DPF_2011_SUSY_b-jets.pdf

75 Interpretation of SUSY Searches in ATLAS with Simplified Models

We present the status of interpretations of Supersymmetry searches in ATLAS using simplified models. Such models allow a systematic scan through the phase space in the sparticle mass plane, and in the corresponding final state kinematics. Models at various levels of simplification have been studied in ATLAS. The results can be extrapolated to more general new physics models which lead to the same event topology with similar mass hierarchies.

Speaker: Hideki Okawa (UC Irvine)

Slides 310_HidekiOkawa.pdf

CP-Violation

Conveners: Enrico Lunghi (Indiana University), Jim Olsen (Princeton University)

76 CP violation - minireview

I will review the present status of CP violating observables in low energy observables and the progress in their precision that can be expected for in the future. I will discuss what deviations from Standard Model can potentially teach us about new physics and also discuss recent hints of non-Standard Model CP violating sources in heavy quark transitions.

Speaker: Jure Zupan (Unknown)

Slides DPF_Aug11.pdf

77 Anomalous like-sign dimuon charge asymmetry at D0

We present an improved measurement of the charge asymmetry $A$ of like-sign dimuon events in 9 fb$^{-1}$ of $p\overline{p}$ collisions recorded with the D0 detector at a center-of-mass energy $\sqrt{s} = 1.96$ TeV at the Fermilab Tevatron collider. From $A$, we extract the like-sign dimuon charge asymmetry in semileptonic $b$-hadron decays. We also study the dependence of charge asymmetry on muon impact parameter. Additional constraints on the $CP$ violation in the $B$ meson sector are also derived from a measurement of the flavor-specific semileptonic asymmetry in the $B^0_d\to\mu D+X$ channel.

Speaker: Bruce Hoeneisen (Universidad San Francisco de Quito)

Slides talk_dimuasym_2011_DPF_140711.pdf

78 Probing CP violating anomalous top-quark couplings at Hadron Colliders

In this talk, I will discuss T-odd correlations induced by CP violating anomalous top-quark couplings at both production and decay level in the context of the Tevatron and the Large hadron collider. We will also show that by simply making use of four momenta of the top decay products it is possible to isolate such effects. With specific examples of top decay modes the experimental sensitivities for the aforementioned coupling will also be discussed.

Speaker: Dr Sudhir Gupta (Iowa State University)

Slides cpxdpf11.pdf

Detector Technology and R&D: Chaired by Kevin Pitts

Conveners: James Brau (Univ. of Oregon), Maurice Garcia-Sciveres (LBNL)

79 Performance of the b-tagging algorithms with an upgraded CMS detector

Identification of jets originating from b quarks (b-tagging) will likely continue to be a key element of many physics analyses at the upgraded HL-LHC where much higher pileup can significantly reduce the performance. An upgrade of the CMS pixel detector proposed for the Phase 1 HL-LHC should enable CMS to maintain the current level of b-tagging performance even in the presence of very high pileup. Results of Monte Carlo simulation studies with an upgrade CMS pixel detector will be presented for tracking and b-tagging performance and compared to that for the current CMS detector.

Speaker: Eric Charles Brownson (Department of Physics and Astronomy-Vanderbilt University)

Slides 2011_08_09_DPF2011_brownson.pdf 2011_08_09_DPF2011_brownson.ppt

80 Belle II Detector: Status and Proposed US Contribution

Over the course of the last decade, the Belle detector at the KEKB collider has collected over 1 ab^{-1} of integrated luminosity, allowing for a number of precision measurements of the Standard Model, including confirmation of the Kobayashi-Maskawa mechanism of CP violation. In June of 2010, KEKB and Belle were shut down to begin upgrading both the accelerator and detector. The increased luminosity of the new accelerator, Super-KEKB, coupled with significant improvements in background rejection and sensitivity of the upgraded detector, Belle II, will ultimately provide a dataset approximately 50 times larger than that obtained with Belle. The US groups in Belle II have chosen to focus their efforts on areas of the detector that will have high impact on the physics and that match their expertise and experience: high precision particle identification (especially at higher momenta), muon/KL identification and monitoring of the electron-positron beams - during commissioning and operation. In this presentation, we review the plans and status of the SuperKEKB/Belle II upgrade. Additionally, we describe the proposed US contributions to Belle II which take advantage of –and leverage– US expertise in detector and electronics design, accelerator instrumentation, and existing US facilities.

Speaker: James Fast (Pacific Northwest National Laboratory)

Slides Belle_II_PNNL-SA-81933_DPF2011.pdf Belle_II_PNNL-SA-81933_DPF2011.ppt

81 ATLAS pixel detector upgrades

The ATLAS experiment is building an "Insertable B-Layer" (IBL) pixel detector to be installed on a replacement beam pipe in 2013. This detector is using the new FE-I4 pixel readout chip recently developed. The IBL will fit inside and not alter the existing ATLAS pixel detector. However, the possibility is being studied to replace the pixel whole detector in 2017 with a lower mass, higher performance instrument based on the FE-I4 chip and new mechanical structures.

Speaker: Mauricio Garcia-Sciveres (LBNL)

Slides atlas-pixels-DPF.pdf

82 Study of the readout chip and silicon sensor degradation for the CMS pixel upgrade

Hybrid silicon pixel detectors are currently used in the innermost tracking system of the Compact Muon Solenoid (CMS) experiment. Radiation tolerance up to fluences expected for a few years of running of Large Hadron Collider (LHC) has already been proved, although some degradation of the part of the silicon detector closer to the interaction point is expected. During the LHC upgrade phases, the level of dose foreseen for the silicon pixel detector will be much higher. To face this aspect, dedicated irradiation tests with fluences above $\mathcal{O (10^{15})$~n$_{\textrm{eq}}$/cm$^2$ have been performed on the silicon sensor and readout chip. Changes in the operation of the sensor and readout chip as a function of the fluence are presented. The charge collection efficiency has been studied: partial recovery of the detector efficiency can be achieved by operating the detectors in a controlled environment and at higher bias voltage.

Speaker: gemma Tinti (Department of Physics and Astronomy-University of Kansas)

Slides PixelRadiationHardness_final.pdf

83 Chronopixel Detector Development for Vertex Detectors for future e+e- Colliders

Studies carried out in the U.S., Europe, and Asia, have demonstrated the power of a pixel vertex detector in physics investigations at a future high energy linear collider. At one time, silicon CCD’s (Charged Coupled Devices) seemed like the detector elements of choice for vertex detectors for future Linear e+ e- Colliders. However, with the decision for a cold TESLA-like superconducting technology for the future International Linear Collider (ILC), the usefulness of CCD’s for vertex detection has become problematical. The time structure of this cold technology is such that it necessitates an extremely fast readout of the vertex detector elements and thus CCD’s as we know them will not be useful. New CCD architectures are under development but have yet to achieve the required performance. For these reasons there is an increased importance on the development of Monolithic CMOS pixel detectors that allow extremely fast non sequential readout of only those pixels that have hits in them. This feature significantly decreases the readout time required. Recognizing the potential of a Monolithic CMOS detector, we initiated an R&D effort to develop such devices3. Another important feature of our present conceptual design for these CMOS detectors is the possibility of putting a time stamp on each hit with sufficient precision to assign each hit to a particular bunch crossing. This significantly reduces the effective backgrounds in that in the reconstruction of any particular event of interest we only need to consider those hits in the vertex detectors that come from the same bunch crossing. The current Chronopixel design is for chips up to 12.5 cm x 2.0 cm in size with a single layer of 10 µ m x 10 µ m charge sensitive pixels. Each pixel has its own electronics under it, but both the sensitive layer and the electronics are made of one piece of silicon (monolithic CMOS) which can be thinned to a total thickness of 50 to 100 µ m, with no need for indium bump bonds. The electronics for each pixel will detect hits above an adjustable threshold. For each hit the time of the hit is stored in each pixel, up to a total of four different hit times per pixel, with sufficient precision to assign each hit to a particular beam crossing (thus the name “chronopixels” for this device). Hits will be accumulated for the 2820 beam crossing of a bunch train and the chip is read out during the 200 millisec gap between bunch trains. There is sufficient intelligence in each pixel so that only pixels with one or more hits are read out, with the x,y coordinates and the time t for each hit. With 10 micron size pixels we do not need analog information to reach a 3 to 4 micron precision so at the present we plan on digital read out, considerably simplifying the read out electronics. We have developed a design, in collaboration with SARNOFF Research Labs of Princeton,N.J., of the Chronopixel devices that satisfy the requirements of the proposed ILC. The detailed design has been completed and SARNOFF has fabricated the first set of prototype devices. We have designed and built, with the help of SLAC, the electronics to test these prototypes. We have completed the test of the first prototypes. We found that they mostly work as designed but have some design flaws. In consultation with SARNOFF we defined the parameters for the second set of prototypes, correcting the flaws of the first prototype and further improving the design,The detailed design of the second prototype is now in progress at SARNOFF and we expect the fabrication of the second prototype to be completed later this year. The design of these Chronopixel detectors, the results of the tests of the first prototypes, and the design of the second prototype, will be presented.

Speaker: Prof. Charles Baltay (Yale University)

Slides 164_BaltayAug2011.pdf 164_BaltayAug2011.ppt

84 Studies of VCSEL failures in the optical readout systems of the ATLAS silicon trackers and Liquid Argon calorimeters

The readout systems for the ATLAS silicon trackers and liquid argon calorimeters utilize vertical-cavity surface-emitting laser (VCSEL) diodes to communicate between on and off detector readout components. A number of these VCSEL devices have ceased to function well before their expected lifetime. We summarize the failure history and present what has been learned so far about the possible causes, and present lifetime projections for the devices that have not failed.

Speaker: Mark Cooke (LBNL)

Slides mcooke_dpf_vcsel.pdf

Education and Outreach

Conveners: Gregory Snow (University of Nebraska), Michael Barnett (Lawrence Berkeley National Lab)

85 Education and Public Outreach Activities of the Laser Interferometer Gravitational-Wave Observatory

Gravitational waves are produced by some of the most energetic and dramatic phenomena in the Universe: Black holes, neutron stars and supernovae. As powerful as they are are at their sources, gravitational waves are incredibly elusive by the time they reach the Earth. Although gravitational waves were predicted almost a century ago (as a consequence of General Relativity), they still have not been directly detected. In the past few years, the Laser Interferometer Gravitational-wave Observatory (LIGO) and its international partners have been hunting for gravitational waves. The initial LIGO instruments were among the most sensitive scientific instruments on the planet. Their sensitivity will achieve further significant improvement with the current construction of Advanced LIGO. Direct detection of gravitational waves will allow scientists to explore the death throes of stars, the origin of dark energy and the nature of space-time in a way humans never have before. LIGO technology will push the frontiers of science and engineering in many areas, from lasers and materials science to high performance computing. The nascent field of gravitational-wave astronomy and the LIGO project offer many opportunities for effective and inspirational astronomy and physics outreach, and provide a powerful showcase for the attractions and challenges of a career in science and engineering. In this talk we describe the extensive program of public outreach and education activities already undertaken by the LIGO Scientific Collaboration - from traveling exhibits, to student field trips, and more. We will also talk about a number of special events which are being planned for the next few years.

Speaker: Dr Marco Cavaglia (University of Mississippi)

Slides 160_MarcoCavaglia.pdf

86 Getting Science Beyond the Research Community: Examples of Education and Outreach from the IceCube Project

The combination of cutting-edge discovery science with the exotic Antarctic environment provides an ideal vehicle to excite and engage a wide audience. Examples of how the International IceCube Collaboration has brought the Universe to the classroom and the general public via the South Pole will be presented.

Speaker: Dr James Madsen (University of Wisconsin River Falls)

Slides APS_DPF_Aug_11_IceCube.ppt

87 Early education activities at the Sanford Underground Laboratory/DUSEL

The Deep Underground Science and Engineering Laboratory (DUSEL) – proposed for the site of the former Homestake Goldmine in Lead, SD – will provide the facility and infrastructure for scientists to study some of the most compelling questions about the history and fate of our universe through its major experiments searching for direct evidence of dark matter and exploring the nature of neutrinos. The Sanford Underground Laboratory at Homestake - operated by the South Dakota Science and Technology Authority - is currently preparing the site and hosting early science and education activities. The Sanford Center for Science Education (SCSE) is in the planning stages as the education component of DUSEL. The mission of the SCSE is to draw upon the science and engineering of DUSEL, its human resources, its unique facility and its setting within the Black Hills to inspire and prepare future generations of scientists, engineers, and science educators. As work proceeds towards design of the building, institution, and the programs and exhibits therein, early work has progressed towards establishing programs that build capacity and partnerships and begin to prototype innovative educational programming and exhibits to meet its educational vision. As the Sanford Lab/DUSEL education team explores innovative ways to convey the excitement of DUSEL physics to audiences of all ages, successes and challenges from the first two years of early educational programming will be highlighted in this talk. Examples include: For Students: • The Davis-Bahcall Scholars Program • Development of a conceptual modern physics course for K-12 For educators • Professional development workshops For the public • Deep science lecture series • Neutrino Days Cultural connections • Finding intersections between American Indian ways of knowing and modern cosmology

Speaker: Margaret Norris (Sanford Underground Laboratory)

Slides

• DPF_0811.pdf
• DPF_0811.pptx
• DPF_0811.pptx

88 Education and Public Outreach of the Pierre Auger Observatory

The scale and scope of the physics studied at the Auger Observatory offer significant opportunities for original outreach work. Education, outreach and public relations of the Auger collaboration are coordinated in a separate task whose goals are to encourage and support a wide range of education and outreach efforts that link schools and the public with the Auger scientists and the science of cosmic rays, particle physics, and associated technologies. The presentation will focus on the impact of the collaboration in Mendoza Province, Argentina, as: the Auger Visitor Center in Malargüe that has hosted over 60,000 visitors since 2001 and a third collaboration-sponsored science fair held on the Observatory campus in November 2010. The Rural Schools Program, which is run by Observatory staff and which brings cosmic-ray science and infrastructure improvements to remote schools, will be highlighted. Numerous online resources, video documentaries, and animations of extensive air showers have been created for wide public release. Increasingly, collaborators draw on these resources to develop Auger related displays and outreach events at their institutions and in public settings to disseminate the science and successes of the Observatory worldwide.

Speaker: Prof. Gregory Snow (University of Nebraska)

Slides auger_snow_DPF2011.ppt

89 HiSPARC: On the interface between outreach and scientific research

The HiSPARC project is a high school cosmic ray project that originated in the Netherlands. The aim of this project is to have high school students participate in building and running a scientific project, thereby increasing their enthusiasm for science in general. We are experimenting with different detector configurations, performing a calibration on the KASCADE site, and exploring the physics of a distributed setup. At the same time, we are moving cosmic ray physics in the standard curriculum of the Dutch high schools. Furthermore, there is an international expansion. Recently, a HiSPARC cluster was realized in Aarhus, Denmark, and work is underway on clusters in the United Kingdom.

Speaker: Dr Charles Timmermans (Radboud University, Nijmegen, Netherlands)

Slides DPF2011_HiSPARC.pptx

90 MARIACHI: Science by Scientists, Teachers and Students

The MARIACHI initiative involves a community with diverse academic backgrounds to explore forefront science. We focus on the study of cosmic rays. Our flagship theme has been the development of a new technology for the detection of cosmic rays, namely forward scattering radar. Over the years many other research subjects have been added to the list of our interests and they are now in various stages of development. We believe that by creating an environment where teachers and students can work together in the pursuit of science, each can learn about science first hand. In this presentation we will give an overview of the experiment and lessons learned. In particular we will discuss how large numbers of students get involved in the data analysis from the experiment. Impressions about the educational impacts will be given.

Speaker: Dr Helio Takai (Physics Department, Brookhaven National Laboratory)

Slides APS2011-Takai.pdf

91 The Multimedia Project Quarked!

Can exposure to fundamental ideas about the nature of matter help motivate children in math and science and support the development of their understanding of these ideas later? Physicists, designers, and museum educators at the University of Kansas created the Quarked!™ Adventures in the subatomic Universe project to provide an opportunity for youth to explore the subatomic world in a fun and user friendly way. The project components include a website (www.quarked.org) and facilitated hands-on shows. These are described and assessment results are presented. Questions addressed include the following. Can you engage elementary and middle school aged children with concepts related to particle physics? Can young children make sense of something they can’t directly see? Do teachers think the material is relevant to their students?

Speaker: Prof. Alice Bean (Department of Physics and Astronomy)

Slides dpf-08-09-11b.pdf

92 Plain English Summaries of Experimental Results

Press releases are issued by labs when a major result such as a discovery is announced. More commonly, we write papers that are not worthy of a press release. Nonetheless, many in the public are quite interested to see progress in our experiments. Tevatron experiments have pioneered plain English summaries of experimental papers, and the concept is spreading to the LHC experiments. It is difficult to write a good plain English summary. We should develop this art-form further.

Speaker: Michael Barnett (Lawrence Berkeley National Lab)

Slides dpf_8_11_parallel.pdf dpf_8_11_parallel.ppt

Electroweak Physics

Conveners: Prof. Doreen Wackeroth (SUNY at Buffalo), Prof. Sridhara Dasu (University of Wisconsin)

93 Z boson property at Tevatron: angular coefficients and Afb of Drell-Yan process

We report on the first measurement of the angular distribution of final state lepton and also the forward and backward asymmetry (Afb) which is sensitive to Weinberg angle in $p\bar{p} \to \gamma^{*}/Z \to \ell^{+}\ell^{-} + X$ events produced at $\sqrt{s}=1.96 TeV$. The data sample collected by the CDF II detector. The angular distributions are studied as a function of the transverse momentum of the lepton pair. The Lam-Tung relation which is only valid for a spin-1 description of the gluon is also tested.

Speaker: Jiyeon Han (University of Rochester)

Slides dpf_angular_aug_09_2011.pdf

94 Studies of Z/gamma* differential cross sections in ppbar collisions with the D0 detector

We use up to 7.3 fb-1 of ppbar collisions collected with the D0 detector study different differential distributions for Z/gamma* produced in ppbar collisions at the Tevatron collider. In one study we investigate the transverse momentum distribution of the Z/gamma* boson by using a novel observable that has reduced sensitivity to the effects of experimental resolution and efficiency, allowing detailed investigations of QCD predictions for the dependence of the Z boson transverse momentum on its rapidity. In a second study we investigate the angular distribution of the Z/gamma* decay products as a function of their invariant mass and derive measurements of the electroweak mixing angle and of the Z-light quark couplings.

Speaker: Rafael Lopes de Sa (Stony Brook University)

Slides 204_RafaelLopesdeSa.pdf

95 Measurement of W and Z boson production rate and asymmetry at CMS

We report the measurements of the rates and asymmetries of inclusive and differential production of W and Z vector bosons in pp collisions at 7 TeV c.m. energy at the CMS detector.

Speaker: Ji Yeon Han (University of Rochester)

Slides cms_dpf_talk_updatev2.pdf

96 Rates of Jets Produced in Association with W and Z Bosons

We present a study of jets produced in association with vector bosons production in pp collisions at center-of-mass energy of 7 TeV using the full CMS 2010 data set, corresponding to 36 pb−1. The transverse energy distribution of the reconstructed leading jets is measured and compared to theoretical expectations. The jet multiplicity distributions are efficiency corrected and unfolded . The ratios of multiplicities, sigma(V+n+1)/sigma(V+n) and sigma(W +n)/sigma(Z +n) where n stands for n jets, are also presented.

Speaker: Kira Suzanne Grogg (Department of Physics-University of Wisconsin)

Slides groggVJets_110809.pdf

97 A Measurement of the Ratio of the W+ 1 Jet to Z + 1 Jet Cross Sections with ATLAS

The measurement of hadronic activity recoiling against W and Z vector bosons provides an important test of perturbative QCD, as well as a method of searching for new physics in a model independent fashion. We present a study of the cross-section ratio for the production of W and Z gauge bosons in association with exactly one jet R-jets= (W+1jet)/(Z+1jet), in pp collisions at sqrt(s) = 7 TeV. The study is performed in the electron and muon channels with data collected with the ATLAS detector at the LHC. The ratio R-jets is studied as a function of the cumulative transverse momentum pT distribution of the jet. Residual systematic uncertainties are parameterized in the same pT distribution. This result can be compared to NLO pQCD calculations and the prediction from LO matrix element + parton shower generators.

Speaker: Mr Andrew Robert Meade (University of Massachusetts)

Slides DPF_rjets2011_080911.pdf

Heavy Ion Physics/Hot and Dense QCD

Conveners: Derek Teaney (Stony Brook University), Prof. Olga Evdokimov (UIC)

98 Hydrodynamic flow in Pb+Pb collisions observed via azimuthal angle correlations of charged hadrons

Azimuthal angle correlations of charged hadrons were measured in $\sqrt s_{NN}$ = 2.76 TeV Pb+Pb collisions by the CMS experiment. The distributions exhibit anisotropies that are correlated with the event-by-event orientation of the reaction plane. Several methods were employed to extract the strength of the signal: the event-plane, cumulant and Lee-Yang Zeros methods. These methods have different sensitivity to correlations that are not caused by the collective motion in the system (non-flow correlations due to jets, resonance decays, and quantum correlations). The second Fourier coefficient of the charged hadron azimuthal distributions was measured as a function of transverse momentum, pseudorapidity and centrality in a broad kinematic range: $0.3 < p_T < 12.0$ GeV/c, $|\eta| < 2.4)$, as a function of collision centrality. In addition, first results on odd Fourier components will be presented and their connection to the hydrodynamic medium will be discussed.

Speaker: Charles Felix Maguire (Department of Physics and Astronomy-Vanderbilt University)

Slides DPF2011_Flow_CFMaguire_UploadV1.pdf

99 Conformal hydrodynamics in Minkowski and de Sitter spacetimes

I will show how to generate non-trivial analytic solutions to the conformally invariant, relativistic fluid dynamic equations by appealing to the Weyl covariance of the stress tensor. The technique I will present recasts the relativistic conformally invariant Navier-Stokes equations in four-dimensional Minkowski space as a static flow in three-dimensional de Sitter space times a line. The solution obtained can be thought of as a generalization of Bjorken flow. The simplicity of the de Sitter form of the flow enables a study of second order viscous corrections and linearized perturbations.

Speaker: Amos Yarom (Princeton University)

Slides DPF_AY.pdf

100 Measurement of elliptic and higher order flow harmonics at $\sqrt{s_{NN}}=2.76TeV$ Pb+Pb collisions with the ATLAS Detector.

The flow harmonics $v_n$ are important bulk observables in heavy ion collisions. They contain information about the initial geometry as well as the transport properties of the medium produced in heavy ion collisions. We present the measurements of flow harmonics $v_2$-$v_6$ using the EP method and two particle correlations method in broad $p_T$, $\eta$ and centrality ranges using the ATLAS detector at LHC. ATLAS recorded, 9ub-1 Pb+Pb data in the 2010 heavy ion run. This large dataset and large detector acceptance :2\pi in azimuth and $\pm 2.5$ units in $\eta$ for charged hadrons, allows for a detailed study of the flow harmonics. The phase space regions where the two methods are consistent and where they disagree will be discussed. We show that the novel structures seen in two particle correlations such as the near and away side ridge as well as the so called "mach-cone" are entirely accounted for by the collective flow. Some interesting scaling relations between the $v_n$ will also be shown.

Speaker: Mr Soumya Mohapatra (Department of Physics-State University of New York (SUNY))

Slides Soumya_Talk_DPF2011.pdf Soumya_Talk_DPF2011.pptx

101 Triangularity and Dipole Assymetry in Ideal Hydrodynamics

We introduce a cummulant expansion to parameterize possible initial conditions in heavy ion collisions. We show that the cummulant expansion converges and can systematically reporduce the results of the Glauber type initial conditions. At third order in the gradient expansion, the cummulants are described with the triangularity $\llangle r^3 \cos3(\phi - \psi_{1,3} ) \rrangle$, and a dipole assymetry, $\llangle r^3 \cos(\phi- \psi_{1,3}) \rrangle$. We show that the orientation angle of the dipole assymetry $\psi_{1,3}$ has a $20\%$ assymetry out of plane for mid-central collisons. This leads to a small net $v_1$ out of plane. In peripheral and mid-central collisions the orientation angles $\psi_{1,3}$ and $\psi_{3,3}$ are strongly correlated, but this correlation disappears towards central collisions. We study the ideal hydrodynamic response to these cummulants and determine the associated $v_1/\epsilon_1$ and $v_3/\epsilon_3$ for a massless ideal gas. The space time development of $v_1$ and $v_3$ is clarified with figures. These figures show that $v_1$ and $v_3$ develop towards the edge of the nucleus, and consequently the final spectra are more sensitive to the viscous dynamics of freezeout. The hydrodynamic calculations for $v_3$ is provisionally compared to Alver and Roland fit of STAR inclusive two particle correlation functions. Finally, we propose to measure the $v_1$ associated with the dipole assymetry by measuring $\llangle \cos(\phi - 3\Psi_{R3} + 2\Psi_{R2}) \rrangle $ where $\Psi_{R3}$ is an experimental estimate for the triangular event plane while $\Psi_{R2}$ is the usual quadrupole event plane plane estimate. This experimental measurement would provide convincing evidence for the strong correlation between $\psi_{1,3}$ and $\psi_{3,3}$, and by association the hydrodynamic interpretation of two particle correlations at RHIC.

Speaker: li Yan (Stony Brook University)

Slides triangle_vis_cou.pdf

102 Triangular Flow in Relativistic Heavy Ion Collisions in an Event-by-Event Hybrid Approach

Triangular flow has been shown to be an interesting new observable to gain insights about the properties of hot and dense strongly interacting matter as it is produced in heavy ion collisions at RHIC and LHC. We will present triangular flow results for Au+Au collisions at the highest RHIC energy calculated in a hybrid approach that includes a non-equilibrium initial evolution and an ideal hydrodynamic expansion with a hadronic afterburner in 3+1 dimensions. By comparing the hybrid approach calculation with a pure transport approach, the influence of viscosity is studied. In addition, the potential of triangular flow for constraining the initial state granularity will be discussed. We compare the results from Au+Au collisions at 200 GeV per nucleon to Pb+Pb at LHC energies and find that the fluctuations/v3 values at LHC are surprisingly similar. Furthermore, the longitudinal long-range correlations of the triangular flow event plane angle are explored for initial conditions from a partonic and a hadronic transport approach. We conclude that longitudinal long-range correlations are not a unique signature for flux tube-like initial conditions, but can also be produced by other mechanisms.

Speaker: Hannah Petersen (Duke University)

Slides petersen_dpf11.pdf

Higgs Physics

Conveners: Dr Laura Reina (Florida State University), Prof. Wade Cameron Fisher (Michigan State University)

103 A Search For The Higgs Boson In H --> ZZ--> 2l 2nu Mode

We report on a search for SM Higgs Boson in the mode H --> ZZ--> 2l 2nu conducted by the CMS experiment with the data accumulated during the 2010 & 2011 running of the LHC at sqrt(s) = 7 TeV.

Speaker: Daniele Trocino (Department of Physics-Northeastern University)

Slides HZZllnn_DPF_Trocino.pdf

104 Search for the Higgs boson in the H->gamma gamma decays in proton-antiproton collisions at 1.96 TeV

Recent searches conducted at the Fermilab Tevatron for the Higgs boson in the diphoton decay channel are reported using 7.0/fb and 8.2/fb of data collected at the CDF and D0 experiments respectively. Although the standard model (SM) branching fraction is small, the diphoton final state is appealing due to better diphoton mass resolution compared with dijet final states. In addition, other models --- such as fermiophobic models where the Higgs does not couple to fermions --- predict much larger branching fractions for the diphoton decay. Here, results are presented for both a SM and fermiophobic Higgs boson as well as a SM search based on a combination of the CDF and D0 analyses.

Speaker: Karen Bland (Baylor University)

Slides DPFTalk_080911_Tevatron_Hgamgam.pdf DPFTalk_080911_Tevatron_Hgamgam.ppt

105 Search for Higgs Boson in Diphoton Final State with the ATLAS Detector

Diphoton final state is one of the most sensitive channels to a Higgs search in the low mass region (115GeV-140GeV). The analysis is optimized to search for a Standard Model (SM) Higgs and dominates the SM Higgs combination in the mass range lower than 120GeV. Nevertheless, an inclusive search strategy adopted is also sensitive to find a low mass diphoton resonance that could be predicted by some new physics models.

Speaker: Haichen Wang (University of Wisconsin-Madison)

Slides 142_HaichenWang.pdf

106 Searches for the Higgs boson in VH->VWW->leptons+X decays in p-pbar collisions at sqrt(s)=1.96 TeV

We present searches for the standard model Higgs boson produced via the VH->VWW->leptons+X process at a center-of-mass energy of 1.96 TeV with the CDF and D0 detectors at the Fermilab Tevatron Collider. We require either two like charge-signed leptons (electron or muon) or three charged leptons (electron or muon). These channels provide significant sensitivity in the intermediate Higgs boson mass range. Inclusion of data up to 7.3 inverse fb and recent improvements to the sensitivity will be discussed.

Speaker: Michael Cooke

Slides 524_cooke_-_Higgs_to_SS_or_Trileptons.pdf

107 SUSY QCD Corrections to Higgs-b Production

The dominant production mechanism for Standard Model (SM) Higgs boson is gg->h. However, in certain beyond the SM scenarios, Higgs production with bottom quarks can become dominant due to enhanced bottom quark Yukawa coupling. One such model is the Minimal Supersymmetric Standard Model (MSSM) where the bottom Yukawa coupling to Higgs bosons, including the SM-like Higgs, gets significantly modified for large values of tan(beta) [defined as the ratio of the vacuum expectation values of the up and down type Higgs]. In this talk, I focus on one-loop supersymmetric QCD corrections to the subprocess b g->b h which is the leading order (LO) process in five flavor number PDF scheme (5FNS) when one bottom quark in the final state is tagged. In particular, I investigate the validity of the commonly used Delta_b approximation where one rescales the bottom Yukawa in MSSM in order to include large tan(beta) effects.

Speaker: Prerit Jaiswal (YITP, Stony Brook University)

Slides prerit_dpf11.pdf

Neutrino Physics: Chaired by Ed Kearns

Conveners: , Edward Kearns (Boston University), Sam Zeller (FNAL)

108 Constraints on non-standard neutrino-matter interactions from MINOS

MINOS searches for neutrino oscillations using the disappearance of muon neutrinos between two detectors, over a baseline of 735 km. We recently reported the most precise measurement of neutrino oscillations in the atmospheric sector and the first tagged measurement of antineutrino oscillations. The neutrino mass splitting and mixing angle are measured to be $|\Delta m^{2}| = 2.32_{-0.08}^{+0.12} \times 10^{-3}\,eV^{2}$ and $\sin^{2}2\theta > 0.90$ (90\% C.L.) for an exposure of $7.25 \times 10^{20}$ protons-on-target (PoT). Antineutrino oscillation parameters are measured as $\Delta \overline{m}^{2}=(3.36^{+0.46}_{-0.40}\textrm{(stat.)}\pm0.06\textrm{(syst.)})\times 10^{-3}\,eV^{2}$ and $\sin^{2}(2\overline{\theta})=0.86^{+0.11}_{-0.12}\textrm{(stat.)}\pm0.01\textrm{(syst.)}$ with an exposure of $1.7 \times 10^{20}$ PoT in NuMI antineutrino running mode. We use the apparent difference in neutrino and antineutrino oscillation parameters to constrain non-standard matter interactions which could occur during propagation through the Earth's crust to the far detector.

Speaker: Zeynep Isvan (University of Pittsburgh)

Slides isvan_minos_110809.pdf

109 Neutrino Oscillation Results from T2K

The T2K experiment is a long baseline neutrino oscillation experiment designed to directly measure $\nu_{e}$ appearance, thereby providing a measurement of $\theta_{13}$, the last unknown neutrino mixing angle. In addition, T2K will make precision measurements of $\Delta m_{23}^2 $ and $\sin ^2\left( {2\theta _{23} } \right)$ via measurement of $\nu_{\mu}$ disappearance. To achieve these goals, a beam of muon neutrinos is produced at the Japanese Proton Accelerator Research Complex in Tokai, Japan. At a distance of 280 meters from the the beam origin, a set of detectors has been constructed in order to measure the properties of the beam before oscillation. The Super-Kamiokande detector 295 kilometers away serves as the far detector that measures the beam after oscillation. T2K began the first data taking run in January 2010 and concluded in June 2010 and accumulated 0.323$\times $10$^{20}$ POT. The second data taking run began in November 2010 and concluded in March 2011 and accumulated 1.108$\times $10$^{20}$ POT. I will summarize the results of the analysis from these runs.

Speaker: Glenn Lopez (Stony Brook University)

Slides gdl-APS-DPF-T2KOscillation.pdf

110 NOvA: Present and Future

NOvA is a next generation neutrino oscillation experiment designed to search for muon neutrino to electron neutrino oscillations by comparing electron neutrino event rates in a Near Detector at Fermilab with the rates observed in a large Far Detector at Ash River, Minnesota, 810 km from Fermilab. The detectors are totally active, segmented, liquid scintillator and the Near Detector is located 14 mrad o the NuMI beam axis. The Far Detector has begun construction and will begin taking data in early 2013. The experiment aims to measure the neutrino mixing angle theta_13 and will push the search for electron neutrino appearance beyond the current limits by more than an order of magnitude. For non-zero theta_13, it is possible for NOvA to observe CP violation in neutrinos and establish the neutrino mass hierarchy. The NOvA prototype near detector on the surface (NDOS) began running at Fermilab in November and registered its first neutrinos from the NuMI beam in December 2010. An overview and current status of the experiment will be presented.

Speaker: Dr Gavin Davies (Iowa State University)

Slides 100_GavinSDavies.pdf

111 Daya Bay Neutrino Experiment: Goal, Progress and Schedule

The discovery of neutrino oscillation, as a breakthrough in particle physics, motivated the Daya Bay Neutrino Experiment, which is designed to make a precise measurement of the last unknown neutrino mixing angle theta13, with a sensitivity 0.01 for sin^2(2*theta13), using reactor anti-neutrino from 17.4GW Daya Bay Nuclear Power Plant located in Shenzhen, China. This talk will introduce the goal of this experiment including an overall introduction of site and baseline selection, detector optimization, current construction progress and schedule for expected data taking.

Speaker: Dr Zhe Wang (Brookhaven National Laboratory)

Slides wangzhe_Dayabay_DPF.pdf

112 The 600 Ton ICARUS Liquid Argon Experiment at the LNGS

We review briefly the R&D effort that went into the construction of the 600 Ton Liquid Argon TPC. The detector is operating very well with electron drift distances near 4m. The detector is exposed to the CNGS beam from CERN and is collecting neutrino events. More than 130 Neutrino events have been observed. Other physics goals include exotic proton decay and sterile neutrinos. ICARUS is also a prototype for much larger multikilo Ton detectors being designed around the world.

Speaker: Prof. David Cline (UCLA)

Slides cline_icarussummer1a.pdf cline_icarussummer1a.ppt

113 Status of the Long-Baseline Neutrino Experiment LBNE

LBNE is an experiment being designed to probe the parameters of neutrino mixing accessible through nu_mu to nu_e oscillation measurements at the atmospheric L/E scale. It will consist of a new neutrino beam line and Near Detector complex at Fermilab, and one or more very large Far Detector modules, nominally to be sited underground in the Homestake Mine in South Dakota. In addition to the long-baseline neutrino program, the Far Detector system will enable a variety of other physics studies with unprecedented sensitivity, including searches for nucleon decay and supernova neutrino bursts. We will report on the status of the conceptual design for the experiment, now being finalized in preparation for DOE's CD-1 milestone.

Speaker: Jon Urheim (Indiana University)

Slides DPF2011_urheim.pdf DPF2011_urheim.pptx

Top Quark Physics: Chaired by Kirill Melnikov

Conveners: Reinhard Schwienhorst (Michigan State University), Dr Zack Sullivan (Argonne National Laboratory)

114 A Measurement of the ttbar Cross Section and the Top Quark Mass in the Hadronic Tau + Jets Decay Channel at CDF

We present a measurement of the ttbar cross section as well as the first measurement of the top quark mass in hadronic tau + jets events from 1.96 TeV ppbar collisions at CDF. Events require a single lepton identified as a hadronic tau, missing Et, and 4 jets of which at least one must be tagged as a b jet. Both the cross section and the mass are extracted from unbinned likelihood functions. The cross section uses a Poisson likelihood function based on the observed number of events and the predicted number of signal and background events for a given ttbar cross section. The mass is extracted from a likelihood fit is based on per-event probabilities calculated from leading-order signal (ttbar) and background (W+jets) matrix elements. Our goal is to directly identify this final state for the first time at CDF as well as to provide the first measurement of the top quark mass in this decay channel.

Speaker: Daryl Hare (Rutgers University)

Slides DPF2011_MEATtau.pdf

115 Measurement of Tau Leptons from Top Quark Pair Production and Decay in ATLAS

The top quark can be used as a probe of new physics, particularly when it decays into non-SM particles. One promising example is the decay of a top quark into a charged Higgs boson and b-quark. Charged Higgs bosons occur naturally in extended Higgs sectors and for a wide range of models can decay nearly exclusively into a tau lepton and a neutrino. In this talk, we summarize the searches for tau leptons from SM top quark pair production and decay, and their interpretation as a probe of physics beyond the standard model using the ATLAS detector.

Speaker: Allison McCarn (Department of Physics-Univ. Illinois at Urbana-Champaign)

Slides DPFTalkTopPairTau_2.pdf

116 Top Quark Theoretical Cross Sections and pT and Rapidity Distributions

I present theoretical results for the top quark pair total cross section, and for the top quark transverse momentum and rapidity distributions at Tevatron and LHC energies. I also present results for single top quark production in the t- and s-channels and also via associated production with a W boson. The calculations include approximate NNLO corrections that are derived from NNLL soft-gluon resummation.

Speaker: Prof. Nikolaos Kidonakis (Kennesaw State University)

Slides Kidonakis-top.pdf

117 Measurements of the top quark pair production cross section at 7 TeV

We present several measurements of the top-pair production cross section in proton-proton collisions at the LHC at a centre-of-mass energy of 7 TeV. We use data collected with the CMS experiment during the year 2011. Measurements are presented in the lepton+jets final state, where events are selected by requiring exactly one isolated and highly energetic muon or electron, and at least four jets. In addition the di-lepton final state, consisting of two electrons or muons, at least two jets, and significant missing energy in the transverse plane, is used. We use b-jet identification in order to increase the purity of the selection. We present data-driven techniques to estimate the most important backgrounds, and discuss the systematic uncertainties on the measurements. The results, superseding previous measurements based on 2010 data, are combined and compared with the theory predictions.

Speaker: Sadia Khalil (Kansas State University)

Slides DPF2011-TopPairXSec.pdf DPF2011-TopPairXSec.ppt

118 A standard model explanation of a dijet excess in Wjj at CDF

The observation of a peak in the dijet invariant mass of the Wjj signal by the CDF Collaboration has caused great excitement. We demonstrate that this peak can be explained as the same upward fluctuations CDF observes in both t-channel and s-channel single-top-quark production. A peak in the dijet spectrum is expected, because CDF used a Monte Carlo simulation to subtract the single-top backgrounds instead of data. The D0 Collaboration has a small upward fluctuation in their published t-channel data; and, hence, we predict they would see a small peak in the dijet invariant mass spectrum of Wjj if they used Monte Carlo instead of data to subtract the single-top backgrounds.

Speaker: Prof. Zack Sullivan (Illinois Institute of Technology)

Slides ZSDPF11.pdf

119 Search for new physics in ttbar + MET -> b bbar qqbar qqbar final state in ppbar collisions at sqrt(s) = 1.96 TeV

We present a search for a new particle T' decaying to a top quark via T'-> t + X, where X goes undetected. We use a data sample corresponding to 5.7 inverse fb of integrated luminosity of ppbar collisions with sqrt(s) = 1.96 TeV, collected at Fermilab Tevatron by the CDF II detector. Our search for pair production of T' is focused on the hadronic decay channel, ppbar -> T'Tbar' -> ttbar + XX -> bqqbar bbarqqbar +XX. We interpret our results in terms of a model where T' is an exotic fourth generation quark and X is a dark matter particle. The data are consistent with standard model expectations. We set a limit on the generic production of T'Tbar' -> ttbar + XX, excluding the fourth generation exotic quarks T'at 95% confidence level up to mT' = 400 GeV/c2 for mX < 70 GeV/c2.

Speaker: Marco Bentivegna

Slides Slides for DPF conference 2011 (Marco Bentivegna)

7:00 PM Welcome reception

Art Museum of the Rhode Island School of Design

Wednesday, August 10

8:00 AM Breakfast

Plenary Session

Convener: Jonathan Rosner

120 Field and String Theory

Speaker: Christopher Herzog (Princeton University)

Slides DPF2011progress.pdf

121 QCD: Experiment

Speaker: Prof. Joey Huston (Michigan State University)

Slides qcd_plenary_dpf.pdf qcd_plenary_dpf.pptx

122 QCD: Theory

Speaker: Prof. Christian Bauer (UC Berkeley)

Slides DPF2011.pdf

10:00 AM Coffee

Plenary Session

Convener: Alice Bean (Department of Physics and Astronomy-University of Kansas)

123 Hadron Spectroscopy

Speaker: Adam Szczepaniak (Indiana University)

Slides dpf-adam-szczepaniak.pdf dpf-adam-szczepaniak.ppt

124 Liquid Quark-Gluon Plasma: Opportunities and Challenges

Speaker: KRISHNA Rajagopal (MIT)

Slides 39_RajagopalTalk.pdf

125 Heavy Ion Physics

Speaker: Barbara Jacak (Stony Brook University)

Slides DPF_aug11_Jacak.pdf DPF_aug11_Jacak.pptx

126 Education & Outreach

Speaker: Michael Barnett (Physics Division-Lawrence Berkeley National Lab. (LBNL))

Slides dpf_8_11_no_videos.pdf dpf_8_11_no_videos.ppt

12:30 PM Lunch

Physics Opportunities with Project X

127 Fermilab Strategy with LBNE and Project X

Speaker: Dr Pier Oddone (Fermilab)

128 Project X: Accelerator and Physics

Speakers: Brendan Casey (Fermilab), Stephen Holmes (Fermilab)

Slides holmes_casey-px-dpf-081011-v6.pptx

129 DOE Sponsored Intensity Frontier Workshop

Speaker: Dr Michael Procario (DOE, Office of Science)

Slides

• DPF_2011_workshop.pdf
• DPF_2011_workshop.pptx
• DPF_2011_workshop.pptx

130 Q/A

Accelerator Physics

Conveners: R. Joel England (SLAC), Dr Vladimir Shiltsev (Fermilab)

131 Project-X: stepping stone for future accelerator-based HEP at Fermilab

Fermilab is leading an international consortium to develop the design of “Project-X” which is an accelerator complex based on a new H- linac that will drive a broad range of experiments at the Intensity Frontier. Project X will provide multi-MW beams from the Main Injector over the energy range 60-120 GeV, simultaneous with mult-MW beams at 3 GeV. The Project-X research program includes world-leading sensitivity in long-baseline neutrino experiments, neutrino scattering experiments, and a rich program of ultra-rare decay and electric dipole moment experiments that are sensitive to most new physics scenarios beyond the Standard Model. Shared technology development with the International Linear Collider and the Muon Collider will establish a bridge to future facilities at the energy frontier. This talk will describe the Project-X accelerator configuration, associated performance projections, status of the accelerator and research program R&D and the strategy for moving forward.

Speaker: Bob Tschirhart (-Fermilab)

Slides ProjectX_DPF_2011.pdf ProjectX_DPF_2011.ppt

132 eRHIC collider design status

We pre­sent the de­sign of fu­ture high-en­er­gy high-lu­mi­nos­i­ty elec­tron-hadron col­lid­er at RHIC called eRHIC. We plan on adding 20 (po­ten­tial­ly 30) GeV en­er­gy re­cov­ery linacs to ac­cel­er­ate and to col­lide po­lar­ized and un­po­lar­ized elec­trons with hadrons in RHIC. The cen­ter-of-mass en­er­gy of eRHIC will range from 30 to 200 GeV. The lu­mi­nos­i­ty ex­ceed­ing 1034 cm-2 s-1 can be achieved in eRHIC using the low-be­ta in­ter­ac­tion re­gion with a 10 mrad crab cross­ing. We re­port on the progress of im­por­tant eRHIC R&D such as the high-cur­rent po­lar­ized elec­tron source, the co­her­ent elec­tron cool­ing and the com­pact mag­nets for re­cir­cu­lat­ing pass­es. A nat­u­ral stag­ing sce­nario of step-by-step in­creas­es of the elec­tron beam en­er­gy by bui­lid­ing-up of eRHIC's SRF linacs and a po­ten­tial of adding po­lar­ized positrons are also pre­sent­ed.

Speaker:

Slides 441_Litvinenko_eRHIC_status.ppt 441_Litvinenko.PDF

133 Muon Collider Progress: Accelerators

A muon collider would be a powerful tool for exploring the energy-frontier with leptons, and would complement the studies now under way at the LHC. Such a device would offer several important benefits. Muons, like electrons, are point particles so the full center-of-mass energy is available for particle production. Moreover, on account of their higher mass, muons give rise to very little synchrotron radiation and produce very little beamstrahlung. The first feature permits the use of a circular collider that can make efficient use of the expensive RF system and whose footprint is compatible with an existing laboratory site. The second feature leads to a relatively narrow energy spread at the collision point. Designing an accelerator complex for a muon collider is a challenging task. Firstly, the muons are produced as a tertiary beam, so a high-power proton beam and a target that can withstand it are needed to provide the required luminosity of ~1 x 10^34 cm^–2s^–1. Secondly, the beam is initially produced with a large 6D phase space, which necessitates a scheme for reducing the muon beam emittance (“cooling”). Finally, the muon has a short lifetime so all beam manipulations must be done very rapidly. The Muon Accelerator Program, led by Fermilab and including a number of U.S. national laboratories and universities, has undertaken design and R&D activities aimed toward the eventual construction of a muon collider. Design features of such a facility and the supporting R&D program will be described.

Speaker: Dr Michael Zisman (Lawrence Berkeley National Laboratory)

Slides MC_talk-8-9-11-Zisman-R2b-abridged.pdf MC_talk-8-9-11-Zisman-R2b-abridged.ppt

Beyond the Standard Model

Convener: Dr Ariel Schwartzman (SLAC)

134 The ATLAS Search for Resonances in the Inclusive Dijet Final State

I present the latest result from the ATLAS search for resonant production of new particles decaying in two jets, using data taken in 2011.

Speaker: Dr Georgios Choudalakis (University of Chicago, Enrico Fermi Institute)

Slides 110810_dijet_DPF2011.pdf

135 Search for high mass dilepton resonances in pp collisions at sqrt(s)=7 TeV with the ATLAS experiment

The ATLAS detector has been used to search for high mass e e or mu mu resonances, such as new heavy neutral gauge bosons. This talk will present the latest search results for a high mass state decaying to dilepton pairs, in proton-proton collisions at a center of mass energy of 7 TeV at the Large Hadron Collider using data recorded by the ATLAS experiment in 2011.

Speaker: Mr Dominick Olivito (University of Pennsylvania)

Slides olivito_zprime_dpf2011.v4.pdf

136 Search for Randall-Sundrum Gravitons at the LHC, Recent Results from the ATLAS Collaboration

With a substantial increase in luminosity at the LHC, 2011 is an exciting time for searches for new physics. The Randall-Sundrum model, in which a warped extra dimension is introduced to resolve the hierarchy problem, predicts a spectrum of massive excited gravitons. There is significant potential for discovery of the lightest of these gravitons. The latest results from the ATLAS Collaboration for RS gravitons decaying to diphoton and dielectron final states will be presented.

Speaker: Mr Evan Wulf (Columbia University)

Slides evan_wulf_RS_diphoton_dpf.pdf

137 Searches for Large Extra Dimensions at CMS

Results of searches for Large Extra Dimensions (LED) in pp collisions at the center-of-mass energy of 7 TeV with the CMS detector are presented. Having analyzed the full 2011 dataset, we found no excess of events above the standard model (SM) expectations. We set stringent limits on the multi dimensional Planck scale as well as masses of exotic objects that are consequences of the LED.

Speaker: Alexey Ferapontov (Department of Physics-Brown University)

Slides 518_AlexeyFerapontov.pdf

138 Search for GMSB SUSY and extra dimensions in diphoton+missing ET and Z+photon+missing ET final states at D0

We report the result of two searches for final states with either two photons and large missing transverse energy or with a Z boson, a photon and large missing transverse energy, using data collected with the D0 detector at the Fermilab Tevatron collider and corresponding to integrated luminosities of up to 6.3 fb-1. The result of these searches are interpreted in the framework of gauge mediated supersymmetry models and in models with extra dimensions and limits are set on the parameters of these models.

Speaker: Yunhe Xie (Fermilab)

Slides diphoton_MET_DPF2011.pdf

139 Searches for Supersymmetry in Events with Photons and Missing Transverse Energy with the CMS Detector at the LHC

We present the results of searches for Supersymmetry in various topologies that lead to final states with jets, missing transverse momentum and one or two photons or a photon and a lepton. These searches are performed using data collected by the CMS experiment at the LHC in pp-collisions at a center-of-mass energy of 7 TeV. Various data-driven techniques used to measure the Standard Model backgrounds are discussed. The results are interpreted in General Gauge Mediated Supersymmetry breaking models.

Speaker: Duong Hai Nguyen (Department of Physics-Brown University)

Slides gmsb_nguyen_1.pdf

Electroweak Physics

Conveners: Prof. Doreen Wackeroth (SUNY at Buffalo), Prof. Sridhara Dasu (University of Wisconsin)

140 Two-loop corrections to W and Z boson production at high pT

I present new results for the complete two-loop corrections in the soft approximation for W and Z boson production at large transverse momentum. Analytical expressions for the NNLO approximate transverse momentum distributions are derived. Results for W boson production at Tevatron and LHC energies are presented.

Speaker: Prof. Nikolaos Kidonakis (Kennesaw State University)

Slides Kidonakis-W.pdf

141 Measurement of the Transverse Momentum Distribution of Z/gamma* Bosons in 7TeV Proton-Proton Collisions with the ATLAS Detector

I present a measurement of the Z/gamma* transverse momentum (pTZ) distribution in proton-proton collisions at √s=7TeV using Z/gamma*->e+e− and Z/gamma*->μ+μ− decays in data samples corresponding to integrated luminosities of 35 pb^−1 and 40 pb^−1 respectively, taken in 2010 with the ATLAS detector. The normalized pTZ distributions are measured separately for electron and muon decay channels as well as for their combination up to pTZ of 350 GeV. The combined measurement is compared to predictions of perturbative QCD and various event generators.

Speaker: Dr Jianbei Liu (University of Michigan)

Slides DPF2011_ZPt_JianbeiLiu.pdf

142 W boson mass and width measurements at D0

We present a precise measurement of W boson mass measurement in electron decay channel using data collected by the D0 detector at the Fermilab Tevatron collider. A binned likelihood fit method is used to extract the mass information from the transverse mass, the electron transverse momentum and missing transverse energy distributions. We also present a precise direct measurement of W boson width using the events with large transverse mass. The W mass result can be used to put stringent indirect limits on the SM Higgs boson mass.

Speaker: Daniel Boline

Slides wmasswidth_dpf2011.pdf

143 Study of Wgamma and Zgamma production at the LHC

We have used the ATLAS detector to study W and Z bosons produced with high energy photons in pp collisions at sqrt(s) = 7 TeV. We select Wgamma and Zgamma events from the interactions p+p -> l + nu + gamma + X and p+p -> l + l + gamma + X where the lepton is a muon or electron. The photon is required to be isolated and separated from the lepton(s) by dR(l-gamma)>0.7. The measurement is based upon data collected by the ATLAS experiment in 2011. The production cross sections and the kinematic distributions of the leptons and photons are compared to Standard Model predictions and to predicted sources of new physics.

Speaker: Prof. Al Goshaw (Duke University)

Slides Wg-Zg_DPF2011_Goshaw.pdf

144 The Epsilon Expansion via Hypergeometric Functions and Differential Reduction

Higher-order diagrams required for radiative corrections to mixed electroweak and QCD processes at the LHC and anticipated future colliders will require numerically stable representations of the associated Feynman diagrams. The hypergeometric representation supplies an analytic framework that is useful for deriving such stable representations. We discuss the reduction of Feynman diagrams to master integrals, and compare integration-by-parts methods to differential reduction of hypergeometric functions. We describe the problem of constructing higher-order terms in the epsilon expansion, and characterize the functions generated in such expansions.

Speaker: Prof. Scott Yost (The Citadel)

Slides yost-dpf6.pdf

Field and String Theory

Convener: V. Parameswaran Nair (City College of New York)

145 New Mathematics for Old Scattering Amplitudes

Scattering amplitudes have played a central role in quantum field theory since its inception. Recent years have seen remarkable progress in our understanding of their previously hidden mathematical simplicity, and in our ability to compute previously intractable scattering amplitudes, both for theoretical and phenomenological purposes. In this talk I will review several of the latest advances on scattering amplitudes in Yang-Mills theory, including on-shell methods and new mathematical technology for dealing with multi-loop amplitudes.

Speaker: Marcus Spradlin (Brown University)

Slides dpf-100911.pdf

146 Manifest SO(N) invariance and S-matrices of three-dimensional N=2,4,8 SYM

An on-shell formalism for the computation of S-matrices of SYM theories in three spacetime dimensions will be presented. The framework is a generalization of the spinor-helicity formalism in four dimensions. The formalism will be applied to establish the manifest SO(N) covariance of the on-shell superalgebra relevant to N =2,4 and 8 SYM theories in d=3. The results will be used to argue for the SO(N) invariance of the S-matrices of these theories: a claim which will be proved explicitly for the four-particle scattering amplitudes. Recursion relations relating tree amplitudes of three-dimensional SYM theories will be shown to follow from their four-dimensional counterparts. The results for the four-particle amplitudes will be shown to be verified by tree-level perturbative computations and a unitarity based construction of the integrand corresponding to the leading perturbative correction will also be presented for the N=8 theory. For N=8 SYM, the manifest SO(8) symmetry will be used to develop a map between the color-ordered amplitudes of the SYM and superconformal Chern-Simons theories, providing a direct connection between on-shell observables of D2 and M2-brane theories.

Speaker: Dr Abhishek Agarwal (American Physical Society)

Slides DPF-2011-talk.pdf

147 Minimal Holography: Higher spin gravity from 2d CFTs

It was recently conjectured that higher spin gravity in three dimensions is holographically dual to a simple, exactly solveable conformal field theory called the W_N minimal model. This raises the possibility of tackling some difficult questions in holography or quantum gravity by performing exact computations at all values of the coupling. I will describe the motivation for studying simplified models of holography based on higher spin gravity, and prove that in this particular duality the spectrum matches exactly at large N.

Speaker: Dr Thomas Hartman (Institute for Advanced Study)

Slides hartman-dpf-minimal-holography.pdf

148 Fuzzy Twistors and Emergent Gravity

We describe a novel regulator of four-dimensional N = 4 Super Yang-Mills theory on a four-sphere. The regulator involves a lift of the theory to a large N matrix model on a non-commutative twistor space. As opposed to other known regulators, this regulator naturally retains both gauge invariance, and the symmetries of the spacetime. We present evidence that in the large N limit, the twistor matrix model correctly reproduces gauge theory scattering amplitudes. We further show that the 1 / N corrections describe an emergent gravitational sector which correctly reproduces tree level scattering amplitudes for Einstein gravity.

Speaker: Dr Jonathan Heckman (Institute for Advanced Study)

Slides BrownDPF2011FINAL.pdf BrownDPF2011FINAL.pptx

149 Large Nc Gauge Theories on the Lattice

We will present new results pertaining to large Nc gauge on the lattice. Two main topics will be (a) the phases of three dimensional large Nc gauge theories reduced to two dimensions; (b) single site realization of large Nc gauge theories with adjoint fermions.

Speaker: Rajamani Narayanan (Florida International University)

Slides narayanan.pdf narayanan.ppt

Heavy Flavor Physics: LHC techniques

Conveners: Alexey Petrov (Wayne State University), Prof. Christian Bauer (UC Berkeley), Owen Long (University of California Riverside)

150 b-tagging Algorithms in the CMS experiment

The identification of b-jets is an important ingredient in characterizing top quark events and many new physics scenarios. The b-tagging algorithms developed within the CMS experiment are mainly based on the large lifetime of b-hadrons. The discriminators and variables defined by the various algorithms which characterize b-jets (e.g. track impact parameter, vertex properties) have been studied using data and compared to expectations from Monte Carlo simulations. In addition detailed studies to optimize track selection and assignment to the jet have been performed in different running conditions and compared with simulations. These studies have led to improvements and optimization of the software tools for the high event pileup scenarios during the 2011 LHC running.

Speaker: Gavril Giurgiu (Rowland Dept. of Phys. and Astron.-Johns Hopkins University (JH)

Slides giurgiu_dpf11_btag.pdf giurgiu_dpf11_btag.ppt

151 Efficiency measurement of b-tagging algorithms developed by the CMS experiment

Identification of jets originating from b quarks (b-tagging) is a key element of many physics analyses at the LHC. Various algorithms for b-tagging have been developed by the CMS experiment to identify b-tagged jets with a typical efficiency between 40% and 70% while keeping the rate of mis-identified light quark jets between 0.1% and 10%. An important step, in order to be able to use these tools in physics analysis, is the determination of the efficiency for tagging b-jets. Several methods to measure the efficiencies of the life-time based b-tagging algorithms are presented. Events that have jets with muons are used to enrich a jet sample in heavy flavor content. The efficiency measurement relies on the transverse momentum of the muon relative to the jet axis or on solving a system of equations which incorporate two uncorrected taggers. Another approach uses the number of b-tagged jets in top pair events to estimate the efficiency. The results obtained in 2010 data and the uncertainties obtained with the different techniques are reported.

Speaker: Saptaparna Bhattacharya (Brown University)

Slides btagging-DPF2011.pdf

152 b-Tagging at ATLAS

The ATLAS detector, one of the two general purpose detectors at the LHC, has collected several hundred inverse picobarnes since the start of 2011 running. The large dataset has allowed deeper studies of bottom-quark tagging performance than before possible. Bottom-quark tagging is an important signal/background selection tool used in top analyses, SUSY analyses, Exotics analyses, and Standard Model analyses - anytime heavy flavor is important in the final state. In this talk I will give a very brief overview of ATLAS b-tagging and concentrate on the performance studies, calibrations, and lessons learned with this large dataset.

Speaker: Gordon Watts (Department of Physics-University of Washington)

Slides 2011_-_DPF_-_b-tagging_in_ATLAS.pdf 2011_-_DPF_-_b-tagging_in_ATLAS.pptx

153 Electron Vetos and Taus at ATLAS

I will present strategies used to separate electron signatures from tau lepton signatures with the ATLAS detector, one of the general purpose detectors on the LHC ring at CERN. Taus can decay leptonically, to electrons or muons and neutrinos, or hadronically, to a number of neutral and charged hadrons and neutrinos. These decays happen before the taus reach the inner-most layer of the detector, thus the work of recognizing the tau decay products is challenging. As electron and QCD signatures resemble those of taus, vetos must be applied. The results of those cut-based and multivariate electron veto techniques will be shown.

Speaker: Ms Susie Bedikian (Physics Department-Yale University)

Slides DPF_Bedikian_final_081011.pdf

Heavy Ion Physics/Hot and Dense QCD

Conveners: Derek Teaney (Stony Brook University), Prof. Olga Evdokimov (UIC)

154 Probing hot and dense nuclear matter with particle correlations and jets at RHIC

The high energy nucleus-nucleus collision at RHIC has produced the quark matter where quarks and gluons are believed to be deconfined. Single particle spectra has shown that parton lose significant amount of energy in such medium. It’s therefore important to further explore the medium properties using multi-particle correlations and jets. In this contribution, we present recent results from RHIC on the following related analyses. We will discuss the studies of the "ridge" and the away-side correlation structure in central A+A collisions via multi-particles correlations. Higher order Fourier harmonics extracted from di-hadron correlations in comparison with initial density fluctuation models will be presented. Comparative analysis of hadron correlations with a high-energy particle vs. fully reconstructed jets will also be discussed.

Speaker: Dr Hua Pei (University of Illinois at Chicago)

Slides HuaPei_DPF2011_talk.pdf HuaPei_DPF2011_talk.pptx

155 The Rise and Fall of the Ridge at RHIC and the LHC

The centrality dependence of the low pt ridge correlations exhibits an interesting centrality dependence: it rises quickly with centrality but then in the most central collisions falls again. This centrality dependence is seen for 62.4 GeV, 200 GeV, and 2.76 TeV data. In this talk, I discuss how the rise and fall of the ridge demonstrates that the ridge is connected to the initial eccentricity. I discuss the connection of the away-side correlations to the near-side correlations and also explain why RHIC should collide Pb ions instead of Au ions.

Speaker: Dr Paul Sorensen (BNL)

Slides sorensen_dpf_brown.ppt

156 Untriggered di-hadron correlations in Pb-Pb collisions at $\sqrt{s_{NN}} =$ 2.76 TeV

We present measurements of untriggered di-hadron correlations as a function of centrality in Pb-Pb \sNN collisions, for charged hadrons with $p_{T} > 0.15$ GeV$/c$. These measurements provide a map of the bulk correlation structures in heavy-ion collisions. Contributions to these structures may come from jets, initial density fluctuations, elliptic flow, resonances, and/or momentum conservation. We decompose the measured correlation functions via a multi-parameter fit in order to extract the nearside Gaussian, the longer range $\Delta \eta$ correlation often referred to as the soft ridge. The effect of including higher harmonics ($v_{3}$ and $v_{4}$) in this procedure will be discussed. We investigate how the nearside Gaussian scales with the number of binary collisions. Finally, we show the charge dependence of the nearside Gaussian.

Speaker: Dr Anthony Robert Timmins (University of Houston)

Slides DPFTimminsv2.pdf DPFTimminsv2.ppt

157 Dihadron correlations in PbPb collisions at 2.76 TeV with CMS

Measurements of charged dihadron correlations from the CMS collaboration are presented for PbPb collisions at a center-of-mass energy of 2.76 TeV per nucleon pair over a broad range of pseudorapidity and the full range of azimuthal angle. With its large pseudorapidity coverage, the CMS tracker is ideally suited for detailed analyses of both short and long-range charged hadron correlations at the LHC. For the most central 0-5% collisions, a broadening of the away side dihadron correlation is observed at all pseudorapidities when compared to pp collisions. A significant correlated yield is observed for pairs of particles with small relative azimuthal angle but large longitudinal separation, commonly known as the ridge. The ridge persists out to relative pseudorapidity of 4 units and its effect is found to be stronger than what was previously observed at RHIC. The dependence of the ridge region shape and yield on transverse momentum and collision centrality has been measured. For particles of transverse momentum of 2--4 GeV/c, the ridge is found to be the most prominent when correlated to particles of 2--6 GeV/c, but diminishes at higher momentum. A Fourier analysis of the long-range two-particle correlations will be presented and discussed in the context of CMS measurements of higher order flow coefficients.

Speaker: Yuting Bai (Physics Department-University of Illinois at Chicago)

Slides 534_YutingBai.pdf

158 Sound Propagation on Top of the Fireball

We study the effect that initial state fluctuations have on final particle correlations in heavy ion collisions. More precisely, we focus on the propagation of initial perturbations on top of the expanding fireball using the conformal solution derived by Gubser and Yarom for central collisions. For small perturbations, the hydrodynamic equations are solved by separation of variables and the solutions for different modes are added up to construct initial point-like perturbations, that are then allowed to evolve until freeze-out. The Cooper-Frye prescription is used to determine the final particle distribution. We present the two-particle correlation functions and their Fourier spectra obtained for different viscosities. We find that viscosity kills the higher harmonics, but that the Fourier spectra presents maxima and minima, similar to what is seen in the study of Cosmic Background Radiation. The difference between the first and the second maximum is used to estimate the viscosity of the medium.

Speaker: Pilar Staig (Stony Brook University)

Slides 494_PilarStaig.pdf

Higgs Physics

Conveners: Dr Laura Reina (Florida State University), Prof. Wade Cameron Fisher (Michigan State University)

159 The Beginnings of Spontaneous Symmetry Breaking in Elementary Particle Theory

I will give a theoretical perspective on the topic of symmetry and symmetry breaking, particularly as the basis of the electroweak theory at the time of the initial formulation and development of the Standard Model. I will also briefly discuss some of these ideas restated in more modern terms.

Speaker: Prof. Gerald Guralnik (Brown University, Providence RI 02912, USA)

Slides dpf2011.talk.5.pdf (Protected)

160 Electroweak symmetry breaking and the higgs beyond the standard model

I will provide a concise, coherent overview of electroweak symmetry breaking from a modern perspective, focusing on models that contain a naturally light higgs boson. In particular, I will review theories with supersymmetry and those in which the higgs field is a pseudo-Nambu-Goldstone boson.

Speaker: Prof. Takemichi Okui (Florida State University)

Slides DPF2011BrownU.pdf

161 Search for charged and doubly-charged Higgs boson production in proton-antiproton collisions at 1.96 TeV

We present searches for charged Higgs prodution in decays of top quarks and also pair production of doubly charged Higgs boson decaying to di-tau, di-muon, and muon+tau final states. The searches are performed in proton-antiproton collisions at a centre of mass energy of 1.96 TeV using an integrated luminosity of up to 7 fb-1 collected by the CDF and D0 experiments at the Fermilab Tevatron Colllider. We find no evidence for charged Higgs production and set limits on the production cross-section for a variety of theoretical models. This represents the first search for pair production of doubly-charged Higgs bosons decaying into tau leptons at a hadron collider.

Speaker: Louise Suter

Slides lsuter_chargedHiggs.pdf

162 $H^\pm \rightarrow \chi^\pm \chi^0 \to 3\ell + E_{\mathrm{T}}^{\mathrm{miss}}$ Searches

In some supersymmetric (SUSY) models, a charged Higgs boson ($\rm H^\pm$) can decay into a chargino-neutralino ($\rm\chi^\pm_i \chi^0_j $) pair producing a final state containing three leptons (electron/muon) and missing transverse energy ($3\ell+E_{\mathrm{T}}^{\mathrm{miss}}$). Such a decay could provide extra sensitivity to the $\rm H^\pm$, especially in the region of SUSY parameter space near tan$\beta$ = 7, where the $\rm H^\pm$ decays to Standard Model particles have reduced significance. We present a signature search on ATLAS data, setting an exclusion limit on an excess of $3\ell+E_{\mathrm{T}}^{\mathrm{miss}}$ events over the Standard Model background. Such an excess could be evidence of generic SUSY, the $\rm H^\pm \to \chi^\pm_i \chi^0_j$ decay, or both.

Speaker: Mr Caleb Lampen (University of Arizona)

Slides DPF_August_2011_ChargedHiggs3Lep_Final.pdf

Neutrino Physics: Chaired by Morgan Wascko

Conveners: Danny Marfatia, Sam Zeller (FNAL)

163 Neutrino-Nucleus Interactions

A thorough understanding of the physics of neutrino nucleus scattering continues to evade us even after 50 years of experimental work. This is mainly caused by the challenges of these experiments that include beams with large energy uncertainty, low event rates, and large backgrounds. Progress has been made in recent years with new results from improved experiments. It is important to continue this work as current and near-future neutrino oscillation experiments require better understanding of these neutrino-nucleus interactions. This talk will survey the current state of measurements and models and will examine future prospects for progress.

Speaker: Dr Rex Tayloe (Dept of Physics, Indiana University)

Slides RT_nuNreview.pdf

164 Highlights from MINERvA's first year

The MINERvA detector, operating since 2009 in the NuMI beam line at Fermilab, has collected neutrino and antineutrino scattering data on a variety of nuclear targets. The detector is designed to identify events originating in plastic scintillator, lead, carbon, iron, water, and liquid helium. The goals of the experiment are to measure precisely inclusive and exclusive cross sections for neutrino and antineutrino interactions for these targets. We present preliminary kinematic distributions for charged current quasi-elastic scattering and other processes.

Speaker: Dr Aaron McGowan (University of Rochester)

Slides DPF11_AMcGowan_abstract308.pdf

165 The MINERvA Detector: Description and Performance

The MINERvA experiment is aimed at precisely measuring the cross-sections for various neutrino interaction channels. It is located in Fermilab in an underground cavern in front of the MINOS near detector. MINERvA is a finely-grained scintillator with electromagnetic and hadron calorimetry regions. There are various nuclear targets located inside and in front of the detector for studying nuclear medium effects in neutrino-induced interactions. The installation was completed in March 2010 and since then the detector has been collecting data. In my talk, I will describe the structure of MINERvA detector, calibration procedures, and performance. I will also outline recent physics results related to the nuclear targets part of the detector.

Speaker: Bari Osmanov (University of Florida)

Slides 513_Osmanov.pdf

166 Charged Current Quasi-Elastic Scattering of Muon Neutrinos at the T2K Near Detector

T2K (Tokai-to-Kamioka) is a long-baseline neutrino oscillation experiment designed to search for electron neutrino appearance. An intense off-axis muon neutrino beam produced at the JPARC facility in Tokai is analyzed at two locations, the first a set of detectors 280 m from the production point (ND280) and the second the Super-Kamiokande detector (SK) 295 km away. The ND280 detectors can identify a variety of neutrino interaction processes including the charged current quasi-elastic (CCQE) interactions used in conjunction with the neutrino beam simulation to predict the neutrino flux and energy spectrum at SK. This "golden mode" provides precise measurements of the flux and spectrum and can also be used to measure the neutrino beam's flavor content. This talk will describe the results of the first inclusive charged current rate measurement made at ND280, the ability of the detector to identify exclusive channels, and the latest status of the CCQE measurement at ND280.

Speaker: Mr Brian Kirby (University of British Columbia)

Slides 153_BKirby_T2KND280CCQE_APSDPF_20110810.pdf

167 Neutrino Studies with the T2K P0D Detector

The T2K experiment is an off-axis long baseline neutrino oscillation experiment. It utilizes the intense nu_mu beam generated at the J-PARC accelerator complex in Tokai, Japan. It has a near detector, ND280, at 280m from the proton target, and Super-Kamiokande as far detector at 295 km. The measurements of the neutral current pi0 and single charged current pi+ (as part of CC inclusive) cross-sections on water is necessary to understand the background for measurement of the theta13 mixing angle. However, these cross-sections are not known well in the energy region ~0.6GeV that is the peak energy of the T2K neutrino beam. This work presents the description and operations of P0D detector, a part of the ND280, and the overview of analyses being carried out with this detector.

Speaker: Dmitriy Beznosko (NN Group SUNYSB)

Slides DPF_2011_neutrino_p0d.pdf

Perturbative and non-Perturbative QCD

Conveners: Christina Mesropian (Rockefeller University-Unknown-Unknown), Sean Fleming (University of Arizona)

168 Measurement of three-jet differential cross sections $\boldsymbol{d\sigma_{\text{3jet}} / dM_{\text{3jet}}}$ in $\boldsymbol{p\bar{p}}$ collisions at $\boldsymbol{\sqrt{s}=1.96}$ TeV

We present the first measurement of the inclusive three-jet differential cross section as a function of the invariant mass of the three jets with the largest transverse momenta in an event in $p\bar{p}$ collisions at $\sqrt{s}=1.96\, \mathrm{TeV}$. The measurement is made in different rapidity regions and for different jet transverse momentum requirements and is based on a data set corresponding to an integrated luminosity of $0.7\, \mathrm{fb}^{-1}$ collected with the D0 detector at the Fermilab Tevatron Collider. The results are used to test the three-jet matrix elements in perturbative QCD calculations at next-to-leading order in the strong coupling constant. The data allow discrimination between parametrizations of the parton distribution functions of the proton.

Speaker: Lee Sawyer (College of Engineering and Science-Louisiana Technical Universi)

Slides SawyerDPF2011MultijetXsecs.pdf SawyerDPF2011MultijetXsecs.pptx

169 Measurement of multi-jet cross-sections at ATLAS

Inclusive multi-jet production is studied using the ATLAS detector for proton-proton collisions with a center-of-mass energy of 7 TeV. The data sample corresponds to an integrated luminosity of 2.43 pb^-1, using the first proton-proton data collected by the ATLAS detector in 2010. Results on multi-jet cross sections are presented and compared to both leading-order plus parton-shower Monte Carlo predictions and next-to-leading-order QCD calculations.

Speaker: Dr Matthew Cleary Tamsett (College of Engineering and Science-Louisiana Technical Universit)

Slides 110810_dpf_tamsett_multijet_crosssection.pdf

170 Second-Order Approximate Corrections for QCD Processes

I present generalized formulas for approximate corrections to QCD hard-scattering cross sections through second order in the perturbative expansion. The approximate results are based on recent two-loop calculations for soft and collinear emission near threshold and are illustrated by several applications to strong-interaction processes in hadron colliders.

Speaker: Prof. Nikolaos Kidonakis (Kennesaw State University)

Slides Kidonakis-NNLO.pdf

171 Measurements of W/Z boson production in associations with jets at D0

We present measurements of total and differential cross sections for the production of W or Z bosons in association with jets, including detailed study of the production of heavy flavor jets, using up to 6 fb-1 of ppbar collisions collected with the D0 detector at the Fermilab Tevatron collider. We present measurements of the inclusive W+n jets total cross sections (with n=1-4) and also differential cross sections for the n-th jet transverse momentum and rapidity. We also present measurements of the W/Z+b-jets production, two important background processes in the searches for the Higgs boson. All measurements are compared to NLO QCD calculations and to Monte Carlo simulations.

Speaker: Ashish Kumar (Department of Physics-Physics Faculty-State University of New Y)

Slides 244_kumar.pdf

Top Quark Physics: Chaired by Liang Li

Conveners: Reinhard Schwienhorst (Michigan State University), Dr Zack Sullivan (Argonne National Laboratory)

172 Measurement of t-channel single top quark production at 7 TeV

We present a measurement of the inclusive single top production cross section in proton-proton collisions at the LHC at a centre-of-mass energy of 7 TeV, using data collected with the CMS experiment during the year 2011. The analysis considers decay channels where the W from the top decays into electron-neutrino or muon-neutrino, and makes use of kinematic characteristics of electroweak single top production for the separation of signal from backgrounds using multivariate methods. The result, which supersedes an earlier measurement based on 2010 data, is compared with the most precise standard model theory predictions. In addition, we present measurements of various differential single top quark production cross sections.

Speaker: Dr Thomas Speer (Department of Physics-Brown University)

Slides 87_speer.pdf

173 Single top production in ppbar collisions at sqrt(s)=1.96 TeV with the D0 detector

We present measurements of the single top production cross in ppbar collisions at sqrt(s)=1.96 TeV using data collected with the D0 detector and corresponding to up to 5.4 fb-1 of integrated luminosity. We obtain both measurements of the inclusive production cross section as well measurements for the separate s- and t-channel production processes. These measurements are used to set constraints on the |Vtb| element of the CKM matrix. We also investigate for possible CP violation in the production of single top quarks and for the existence of possible resonances in the s-channel.

Speaker: Reinhard Schwienhorst (Michigan State University)

Slides SingletopDPF2011.pdf

174 Measurement of Top Quark Properties in CDF

The top quark was discovered at the CDF and D0 experiments in 1995.Its properties within the Standard Model are fully defined. The measurement of the top quark mass and the verification of the expected properties have been an important topic of experimental top quark physics since. We will present the recent measurements of top quark properties in CDF.

Speaker: Zhenbin Wu (Baylor University)

Slides DPF_2011.pdf

175 Measurement of Single-top Quark Production with the ATLAS Detector

We use 2011 data from the ATLAS detector to isolate the production of single-top quarks. This electroweak top-quark production is expected to be sensitive to new physics such as flavor changing neutral currents or W' production, and can also be an important background for processes like the Higgs boson production. The data for this analysis are collected from collisions occurring at 7 TeV center-of-mass energy and then several selections are applied to these events. The selections are determined from studies of simulated events and chosen to isolate the signal while removing background events, based on the kinematic signature of the single-top quark process. We report the likelihood that the resulting sample of data events are single-top quarks and discuss the kinematics of this process.

Speaker: Jenny Holzbauer (Michigan State University)

Slides 376_JennyHolzbauer.pdf

176 Search for flavor changing neutral currents in decays of top quarks

We present a search for flavor changing neutral currents in decays of top quarks. The analysis is based on a search for $t\bar{t}\rightarrow\ell'\nu\ell\bar{\ell}$+jets ($\ell, \ell' = e,\mu$) final states using 4.1~{\rm fb}$^{-1}$ of integrated luminosity of $p\bar{p}$ collisions at $\sqrt{s} = 1.96$~{\rm TeV}. We extract limits on the branching ratio $B(t\rightarrow Zq)$ ($q = u, c$ quarks), assuming anomalous $tuZ$ or $tcZ$ couplings. We do not observe any sign of such anomalous coupling and set a limit of $B < 3.2\%$ at 95\% C.L.

Speaker: Carrie McGivern (University of Kansas)

Slides

• DPF_2011_Talk_Final.key
• DPF_2011_Talk_Final.pdf
• DPF_2011_Talk_Final.ppt

4:00 PM Coffee

Accelerator Physics

Conveners: R. Joel England (SLAC), Dr Vladimir Shiltsev (Fermilab)

177 High Gradient RF Progress : Toward Tev-scale Accelerators

Research on the basic physics of high-gradient, high frequency accelerator structures and the associated RF/microwave technology are essential for the future of discovery science, medicine and biology, energy and environment, and national security. We will review the state-of-the-art for the development of high gradient linear accelerators.

Speaker: Prof. Sami Tantawi (SLAC)

Slides HG_for_DPF.pdf

178 Towards 20 T accelerator magnets: a road to super-high energy colliding beams

For a fixed size of a circular collider, its energy is limited by the strength of bending dipole magnets. Moreover, for both linear and circular machines, their maximum luminosity is determined (among other factors) by the strength of quadrupole magnets used for the final beam focusing. That is why there has been a permanent interest to higher-field and higher-field gradient accelerator magnets from the high-energy physics and particle accelerator community. The highest fields in accelerator magnets have been achieved using superconducting electromagnets. The ultimate field of these magnets is limited by the superconductor critical parameters such as critical field Bc2, critical temperature Tc and critical current density Jc. There are two classes of practical superconducting materials suitable for accelerator magnets - so called Low-Temperature Superconductors (NbTi, Nb3Sn, Nb3Al) and High-Temperature Superconductors (BSCCO, YBCO). The maximum field of NbTi accelerator magnets used in all present high-energy machines including LHC is limited by ~10 T at operating temperature ~1.8 K. The magnetic fields above 10 T threshold became possible thanks to the Nb3Sn superconductor. Nb3Sn accelerator magnets can provide operating fields up to ~15 T and significantly increase the coil temperature margin. Accelerator magnets with operating field above 15 T would require using high-field high-temperature superconductors, which have highest upper critical magnetic field Bc2. However, due to the substantially higher cost and lower critical current density in magnetic fields below 15 T, a hybrid approach with Nb3Sn superconductor in fields below 15 T is a quite attractive option even though the Nb3Sn and HTS materials require different coil processing. This paper discusses the status and main results of the state-of-the-art Nb3Sn accelerator magnets and outlines a roadmap towards the 20 T class magnets.

Speaker: Dr Alexander Zlobin (Fermilab)

Slides DPF2011_20T_magnets_zlobin_8_short_version.pdf

179 SRF Technology for Particle Accelerators: Progress Report

The superconducting RF (SRF) technology is increasingly becoming the technology of choice for a wide range of particle accelerators. It has found applications in high energy and nuclear physics accelerators, spallation neutron sources, and light sources. The opportunities offered by the SRF technology, and its challenges, will be presented and reviewed.

Speaker: Prof. Jean Delayen (Old Dominion University)

Slides SRF_TECHNOLOGY_FOR_PARTICLE_ACCELERATORS.pdf

180 High Power, High Energy Cyclotrons for Decay-At-Rest Neutrino Sources: The DAEdALUS Project

Neutrino physics from muon decay is very much at the forefront of today's physics research. Large detectors installed in deep underground locations perform neutrino mass, CP violation, and oscillation studies using long- and short-baseline beams of neutrinos from muons decaying in flight. DAEdALUS looks at neutrinos from stopped muons, “Decay At Rest (DAR)” neutrinos. The DAR neutrino spectrum has no electron antineutrinos (nu-e-bar) (pi-minus are absorbed to level of 10^-4), so a detector with much hydrogen (water-Cherenkov or liquid scintillator) is sensitive to appearance of nu-e-bar’s oscillating from nu-mu-bar via inverse-beta-decay. Oscillations are studied using shorter baselines, less than 20 km reaching the same L/E range as the current and planned neutrino experiments originating at Fermilab. As the neutrino flux is not variable, nor is the energy, the baseline is varied: plans call for 3 accelerator-based neutrino sources at 1.5, 8 and 20 km with staggered beam-on cycles. Key is cost-effectively generating megawatt beams of 800 MeV protons. A superconducting ring cyclotron, accelerating H2+ ions is being designed by L. Calabretta and his group at INFN-LNS-Catania. Having a design peak power of 8 MW, the 5 emA circulating beam is extracted via a stripping foil, avoiding beam-loss problems that would be encountered in classical cyclotron extraction. The molecular hydrogen beam also reduces the severity of space charge effects at the low-energy central region for the injected beam. The system consists of two cascaded cyclotrons, and an axial injection line from an external microwave source. >20 emA of H2+ ions, CW, are seen with an available source. The injector cyclotron will bring beam to 50 MeV/a, and a short transfer line will take beam to the main ~15 meter diameter Ring cyclotron. This will consist of 8 sectors of superconducting magnets, with maximum field of 6 T. Isochronicity is maintained by field design and suitable trim coils. RF cavities between the magnet sectors accelerate the beam. An extraction channel of the lower-rigidity protons exiting the stripper foil is plotted through the highly-variable magnetic field, and exits cleanly from the machine. A large water-cooled graphite target provides the source of neutrinos from pi-mu decays. For DAEdALUS applications, each of the three machines will be run at ~20% duty factor, so events in the detector can be tagged unambiguously with a source. Timing is arbitrary, beam on time for each machine can range from seconds to days. Average power from each source still exceeds 1 MW, providing adequate neutrino flux at the detector for very fine sensitivity to the measurements desired. It should be noted that the original, and even revolutionary design of these accelerators can facilitate many other "ADS" (Accelerator-Driven Systems) applications, such as driving subcritical reactors, waste transmutation, etc.

Speaker: Jose Alonso (MIT-LNS)

Slides Alonso-DAEdALUS-DPF_Brown.pdf

Beyond the Standard Model

Convener: Dr Ariel Schwartzman (SLAC)

181 Search for new physics with same-sign isolated dilepton events with jets and missing transverse energy at CMS

The results of searches for Supersymmetry in events with two same-sign isolated leptons, hadronic jets, and missing transverse energy in the final state are presented. The searches use pp collisions at 7 TeV collected in 2011 by the CMS experiment.

Speaker: Marc Gabriel Weinberg (Department of Physics-University of Wisconsin)

Slides 132_MarcGabrielWeinberg.pdf

182 Search for Chargino-Neutralino Associated Production in Dilepton Final States with Tau Leptons

We present a search for chargino and neutralino supersymmetric particles yielding same signed dilepton final states including one hadronically decaying tau lepton using 6.0 fb^-1 of data collected by the the CDF II detector. This signature is important in SUSY models where, at high \tan{\beta}, the branching ratio of charginos and neutralinos to tau leptons becomes dominant. We study event acceptance, lepton identification cuts, and efficiencies. We set limits on the production cross section as a function of SUSY particle mass for certain generic models.

Speaker: Mr Robert Forrest (UC Davis)

Slides dpf2011.pdf

183 Inclusive Search for Same-Sign Dileptons

We present an inclusive search for events with two isolated leptons ($e$ or $\mu$) of the same electric charge in $pp$ collisions at $\sqrt{s}=7$ TeV. The data are selected from events recorded in the ATLAS detector in 2011. With a small Standard Model background, the same sign dilepton signature is a powerful testing ground for new physics. The distributions of kinematical variables are presented, and compared to the Standard Model predictions.

Speaker: Mr Benjamin Cerio (Physics Department-Duke University)

Slides presentationFinal2.pdf

184 Search for universal extra dimensions and supersymmetry in like-sign dimuon events using 7.3 fb-1 of D0 data

We present a search for universal extra dimensions (UED) and supersymmetry (SUSY) in the two like-sign muons final state. The data set corresponds to an integrated luminosity of 7.3 fb-1 collected by the D0 detector at a $p\bar{p}$ center of mass energy of 1.96 TeV at the Fermilab Tevatron Collider. No evidence for physics beyond the standard model is observed and limits are set on the size of the compactification scale R_c^−1 in the minimal UED model and on the SUSY parameter space in supergravity inspired models.

Speaker: Jason Mansour (University of Göttingen)

Slides talk_dpf11_mansour_ued.pdf

185 Search for Supersymmetry at CMS in events with three or more leptons

A search for physics beyond the Standard Model (SM) is performed using events with at least three leptons and any number of jets. The search is performed in data collected in 2011 by the CMS experiment at the LHC in pp-collisions at a center of mass energy of 7 TeV. Numerous leptonic channels have been investigated in an exclusive manner and data-driven techniques are used to quantify the SM backgrounds. The results are used to constrain hitherto unexplored regions of supersymmetry that have significant multilepton yield at 7 TeV pp-collisions.

Speaker: Sho Maruyama (Department of Physics-University of California Davis (UCD))

Slides ShoMaruyama_DPFv4.pdf

186 Search for multilepton final states of supersymmetry at the ATLAS Detector

The results of a search for supersymmetry in multilepton final states using the ATLAS detector is presented. Such signals require three or more leptons, jets, and missing transverse energy. This channel provides the advantage that the contribution due to standard model backgrounds is expected to be very low. Results from the 2011 data-taking will be reported.

Speaker: Jeremiah Jet Goodson (Department of Physics - State University of New York (SUNY))

Slides jgoodson_DPF2011_multileptons_v7.pdf

187 Missing-ET insensitive search for new physics such as R-parity Violation with multileptons

Anticipating a data sample of the order of hundreds $pb^{-1}$ at a collision energy of 7 TeV by the CMS experiment at LHC in 2011, we probe new physics such as matter symmetry violation in the leptonic sector in theories with partner articles with a signature of three or more leptons in the final state. The search is organized to minimize reliance on specific kinematic variables to reduce SM backgrounds and we illustrate it by application to R-parity violating scenarios of new physics which are not necessarily accompanied by missing ET. We also estimate Standard Model backgrounds for individual channel with a maximal use of data-based methods to avoid reliance on simulation.

Speaker: Sanjay Ravi Ratan Arora (Dept. of Physics and Astronomy-Rutgers, State Univ. of New Jers)

Slides 245_SanjayRArora.pdf

CP-Violation

Conveners: Enrico Lunghi (Indiana University), Jim Olsen (Princeton University)

188 Lattice weak matrix elements and CP violation in the LHC era

The role of lattice matrix elements in refined tests of the Standard Model and for search of new physics will be discussed. Although the results from the lattice in conjunction with data from B-factories provided a confirmation of the CKM-paradigm of CP violation a few years ago, since then improved calculations and better data from experiments is now yielding strong indications that the single phase in the CKM-matrix is not enough. Repercussions for some BSMs will also be discussed

Speaker: Amarjit Soni (BNL)

Slides 447-Lattice_-_Soni.pdf

189 Bs -> J/psi phi at CMS

The Bs meson is studied with the CMS detector at LHC. The time-dependent measurements of the Bs decay into J/Psi Phi and of the rate of the rare decay into mu mu potentially provide indirect constraints on physics beyond the Standard Model. This talk presents the first cross section measurement for Bs->J/Psi phi production based on data taken in 2010 and discusses prospects of the lifetime-difference and CP measurements with CMS.

Speaker: Giordano Cerizza (Department of Physics and Astronomy-College of Arts and Science)

Slides DPFcerizza.pdf

190 Search for CP violation in the Bs - Bsbar system with LHCb

The determination of the mixing induced CP-violating asymmetry in decays such as $B^0_s \to J/\psi \phi$ is one of the key goals of the LHCb experiment. Its value is predicted to be very small in the Standard Model but can be significantly enhanced in many models of New Physics. The steps towards a precise determination of this phase with a flavour-tagged, time-dependent, angular analysis of the decay $B^0_s \to J/\psi \phi$ will be presented, and first results shown from this measurement programme, using data collected in 2010 and the early months of the 2011 run. Results will also be shown, and prospects discussed, from related measurements.

Speaker: Daan Van Eijk (NIKHEF)

Slides talk.pdf

191 Measurement of CP violating parameters in the decay Bs -> J/psi phi

We report a new measurement of the $CP$-violating phase $\phi_s$, of the decay width difference for the two mass eigenstates $\Delta \Gamma_s$, of the mean $B^0_s$ lifetime $\overline{\tau}_s$, and of magnitudes of the decay amplitudes, from the flavor-tagged decay $B^0_s\to J/\psi \phi$. For the first time, we consider possible contributions from the decay $B^0_s \rightarrow J/\psi K^+K^-$, with the $K^+K^-$ in a $s$ wave. This measurement is based on 8 fb$^{-1}$ of $p\overline{p}$ collisions recorded with the D0 detector at a center-of-mass energy $\sqrt{s} = 1.96$ TeV at the Fermilab Tevatron collider.

Speaker: Dr Avdhesh Chandra (Rice University)

Slides talk

192 Long-Distance Dominance of the CP Asymmetry in B->X_{s,d}+gamma Decays

The CP asymmetry in inclusive b-> s gamma decays is an important probe of new physics. The theoretical prediction was thought to be of a perturbative origin. In the standard model the perturbative prediction for the asymmetry is about 0.5 percent. In a recent work with M. Benzke, S.J. Lee and M. Neubert , we have shown that the asymmetry is in fact dominated by non-perturbative effects. Since these are hard to estimate, it reduces the sensitivity to new physics effects. On the other hand, these new non-perturbative effects suggest a new test of new physics by looking at the difference of the CP asymmetries in charged versus neutral B-meson decays.

Speaker: Dr gil paz (The University of Chicago)

Slides DirectCP_gilpaz_DPF2011.pdf

Detector Technology and R&D: Chaired by Andy White

Conveners: James Brau (Univ. of Oregon), Maurice Garcia-Sciveres (LBNL)

193 Status of particle flow calorimetry

Summary of challenges, development, and prospects.

Speaker: Dr Jose Repond (Argonne National Laboratory)

Slides Calorimetry_Providence_Aug_2011.pdf Calorimetry_Providence_Aug_2011.pptx

194 Performance of the CMS Electromagnetic Calorimeter at the LHC

The CMS Electromagnetic Calorimeter (ECAL) is a high resolution, fine grained calorimeter devised to measure photons and electrons at the LHC. Built of lead tungstate crystals, it plays a crucial role in the search for new physics as well as in precision measurements of the Standard Model. A pre-shower detector composed of sandwiches of lead and silicon strips improves pi-0/gamma separation in the forward region. The operation and performance of the ECAL during the 2010 run at the LHC, with pp collisions at √s = 7 TeV will be reviewed, and to some extent for the 2011 running as well. Pure samples of electrons and photons from decays of known resonances have been exploited to improve and verify the trigger efficiency, the reconstruction algorithms, the detector calibration and stability, and the particle identification efficiency. A review of these aspects will be given.

Speaker: Marco Grassi (Universita di Roma I 'La Sapienza'-Universita e INFN, Roma I)

Slides mgrassi-Ecal-Performance.pdf

195 Performance of Particle Identification with the ATLAS Transition Radiation Tracker >

The ATLAS Transition Radiation Tracker (TRT) is the outermost of the three sub-systems of the ATLAS Inner Detector at the Large Hadron Collider at CERN. In addition to its tracking capabilities, the TRT provides particle identification (PID) ability through the detection of transition radiation X-ray photons. The latter functionality provides substantial discriminating power between electrons and hadrons in the momentum range from 1 to 200 GeV. In addition, the measurement of an enhancement of signal time length, which is related to high specific energy deposition (dE/dx), can be used to identify highly ionizing particles, increasing the electron identification capabilities at low momentum and improving the sensitivity of searches for new physics. This talk presents the commissioning of TRT PID during early 2010 7 TeV data taking. Performance in 2010 and 2011 demonstrating the TRT's ability to identify electrons, complementary to calorimeter based identification methods, will also be shown.

Speaker: Elizabeth Hines (Department of Physics and Astronomy-University of Pennsylvania)

Slides HinesDPF10Aug.pdf

196 Calibration and Performance of the ATLAS Muon Spectrometer

The ATLAS muon spectrometer is designed to measure muon momenta with a resolution of 4% @ 100 GeV/c rising to 10% @ 1 TeV/c track momentum. The spectrometer consists of precision tracking and trigger chambers embedded in a 2T magnetic field generated by three large air-core superconducting toroids. The precision detectors provide 50 micron tracking resolution to a pseudo-rapidity of 2.7. The system also includes an optical monitoring system which measures detector positions with 40 micron precision. I will report on the calibration and performance of the ATLAS muon spectrometer in the first year of LHC data.

Speaker: Dr Edward Diehl (University of Michigan)

Slides diehl_dpf_110810.pdf

197 Frequency Scanned Interferometry for ILC Tracker Alignment

In order to exploit fully the physics potential of future lepton colliders, highly precise tracking systems will be needed, for which systematic alignment uncertainties must be small. We describe ongoing R&D in frequency scanned interferometry (FSI) to be applied to alignment monitoring of a detector's charged particle tracking system, in addition to its beam pipe and final-focus quadrupole magnets. In FSI alignment, one measures hundreds of absolute point-to-point distances of detector elements in 3 dimensions by using an array of beams split from a central laser. We report here on progress using a dual-laser FSI single-channel prototype. Dual lasers with oppositely scanned frequency directions permit cancellation of many systematic errors, making the alignment robust against vibrations and environmental disturbances. Under realistic environmental conditions, a precision of about 0.2 microns was achieved for a distance of about 40 cm for the prototype. Work is now under way to demonstrate a multi-channel system on the bench. Recent progress will be summarized.

Speaker: Dr Haijun Yang (University of Michigan)

Slides fsi-dpf2011.pdf

Education and Outreach

Conveners: Michael Barnett (Lawrence Berkeley National Lab), Prof. Snow Gregory (University of Nebraska in Lincoln)

198 Particle Physics Masterclasses

The IPPOG and U.S. particle physics masterclasses took place worldwide in March, 2011. For the first time, all masterclasses used real LHC data. Students in the U.S. masterclasses (that included participants in several countries outside the U.S.) analyzed both ATLAS and CMS data. QuarkNet has been evaluating the U.S. effort since 2008. The design of the LHC masterclasses and the results of this study will be discussed.

Speaker: Kenneth William Cecire (University of Notre Dame)

Paper MCevalrpt_summary.pdf

Slides Cecire_Masterclass.pdf Cecire_Masterclass.pptx

199 CMS Data for High School Teachers and Students

The CMS Collaboration has released more than a quarter of a million 7 TeV proton-proton events that contain pairs of muons, electrons or jets with 2-body invariant masses in the range 0 to 100 GeV for student and teacher investigations. QuarkNet and I2U2 have developed software to exploit these data in a manner similar to that of the front-line physicists: a 3-D web-based event display to understand particle interactions in the detector and a histogramming package to create and examine mass plots after making cuts on the data. An additional package allows the students to produce on-line posters featuring their results. The data include large numbers of events corresponding to the presence of J/psi, W and Z particles, allowing students to make "discoveries". We describe the released data and three initiatives that allow exploration: a student masterclass, a more in-depth web-based "e-Lab" and a summer 2011 teacher workshop to be held at Fermilab.

Speaker: MIke Fetsko (Goodwin High School, Virginia)

Slides Fetsko_CMSdata.pdf Fetsko_CMSdata.ppt

Video CMS_elab.wmv Masterclass_Brief.wmv

200 Classroom Cosmic Rays: Detectors and Analysis

Since 1998, QuarkNet has provided over 500 cosmic ray muon detectors to teachers in the project and collaborators on similar projects. The detector relies on GPS accuracy for time-stamping PMT pulses from four scintillation counters. The DAQ is now in its third revision. Students and teachers use the detector to carry out small experiments to measure properties of cosmic ray muons. Other groups, most international, have purchased the detector for similar uses. We will describe the detector, its installation base and our web-based data-sharing and analysis portal.

Speaker: Thomas Jordan (University of Florida/Fermilab)

Slides JordanDPFAug2011.pdf

201 Bringing the LHC and ATLAS to a planetarium

An outreach effort has started at Michigan State University to bring the physics of the LHC and the ATLAS detector to the Abrams planetarium on the MSU campus. MSU graduate and undergraduate students from Physics as well as from the College of Communication Arts & Sciences are putting together planetarium content on the LHC and its connection to astronomy, the big bang, and dark matter. I will report on this effort and present a first short clip.

Speaker: Prof. Reinhard Schwienhorst (Michigan State University)

Slides DPF2011Planetarium.pdf

Video http://vimeo.com/23508145

202 Celebrating 30 Years of K-12 Educational Programming at Fermilab

In 1980 Leon Lederman started Saturday Morning Physics with a handful of volunteer physicists, around 300 students and all the physics teachers who tagged along. Today Fermilab offers over 30 programs annually with help from 250 staff volunteers and 50 educators, and serves around 40,000 students and 2,500 teachers. Find out why we bother. Over the years we have learned to take advantage of opportunities and confront challenges to offer effective programs for teachers and students alike. We offer research experiences for secondary school teachers and high school students. We collaborate with educators to design and run programs that meet their needs and interests. Popular school programs include classroom presentations, experience-based field trips, and high school tours. Through our work in QuarkNet and I2U2, we make real particle physics data available to high school students in data-driven activities as well as masterclasses and e-Labs. Our professional development activities include a Teacher Resource Center and workshops where teachers participate in authentic learning experiences as their students would. We offer informal classes for kids and host events where children and adults enjoy the world of science. Our website hosts a wealth of online resources. Funded by the U.S. Department of Energy, the National Science Foundation and Fermilab Friends for Science Education, our programs reach out across Illinois, throughout the United States and even around the world. We will review the program portfolio and share comments from the volunteers and participants.

Speaker: Marjorie Bardeen (Fermilab)

Slides 68_MarjorieBardeen.pdf

203 Round Table Discussion

Speaker: Presenters and participants All

Heavy Flavor Physics: EW penguins and Charm

Conveners: Alexey Petrov (Wayne State University), Prof. Christian Bauer (UC Berkeley), Owen Long (University of California Riverside)

204 BABAR Results on Leptonic and Radiative B and Charm Decays

We present present measurements of B and charm flavor changing neutral current processes, including inclusive and exclusive b->s gamma and B -> K nu nubar. We also present results of BABAR studies of leptonic decays of charged B and Ds mesons, in particular B -> tau nu and Ds->tau/mu nu.

Speaker: Brad Wray (University of Texas at Austin)

Slides bwray_dpf_2011.pdf

205 Updated Search for Non-SM Physics in B->K(*)mumu Decays at CDF

We present updated measurements of branching fractions, polarization, and muon forward-backward asymmetry in B-->K mu mu final states using 6.7/fb of data collected by the CDF detector. A search for Lambda_b --> Lambda mu mu decays will also be shown. The results are the most sensitive from a single experiment to date.

Speaker: Prof. Austin Napier (Tufts University)

Slides DPF11_TALK_ANv3_3.pdf

206 Electroweak Penguin decays at LHCb

Promising ways to search for New Physics effects in radiative penguin decays are in the angular analysis of $B^0 \to K^{*} \mu^+\mu^-$, in the measurement of direct CP violation in $B^0 \to K^{*} \gamma$ and a time dependent analysis of $B^0_s \to \phi \gamma$. All of these studies are being pursued at LHCb. First results will be shown from the 2010 and early 2011 data, with particular emphasis on $B^0 \to K^{*} \mu^+ \mu^-$.

Speaker: Thomas Blake (Imperial College Sci., Tech. & Med.)

Slides 8_tblake_dpf.pdf

207 Semileptonic B and Charm Decays with BABAR

We present recent results of studies of semileptonic B and charm decays from BABAR. In particular, we describe a recent measurement of the B-> D(*)tau nu branching fraction, and a study of Bs production and semileptonic decays using BABAR data collected above the Upsilon(4S). We also discuss the determination of |Vub| from exclusive B->pi/rho l nu and and from fully inclusive measurements and present recent branching fraction measurements of B->Lamdba_c p X l nu, B -> Ds K l nu and D+->K-pi+ e nu.

Speaker: Brian Hamilton (University Of Maryland)

Slides Hamilton-DPF-2011-v2.pdf

208 Measurements of Charm Mixing and CP Violation at Belle

We report an improved measurement of D^0-D^0bar mixing using the time dependence of the Dalitz plot of the decay mode D^0->K_S^0 pi^+ pi^-. In addition, we report results of searches for CP violation in the decays D^0->K_S^0 P^0 where P0 denotes a neutral pseudo-scalar meson which is either a pi^0, eta or eta^'. The result for D^0->K_S pi^0 is the most sensitive search for CP violation in the D^0 system to date. These results are based on a large data sample collected by the Belle detector at the KEKB asymmetric energy electron positron collider.

Speaker: Debabrata Mohapatra (Virginia Tech)

Slides Mohapatra.pdf

209 Results and prospects for Charm Physics at LHCb

Precision measurements in charm physics offer a window into a unique sector of potential New Physics interactions. LHCb is well equipped to take advantage of the enormous production cross-section of charm mesons in $pp$ collisions at $\sqrt{s}=7$~TeV. The measurement of the $D^0 -\bar{D^0}$ mixing parameters and the search for CP-violation in the charm sector are key physics goals of the LHCb programme. Results will be shown, based on the data collected in 2010, and the first few months of the 2011 run.

Speaker: Silvia Borghi (University of Glasgow)

Slides DPFLHCbCharm_borghi.pdf

Heavy Ion Physics/Hot and Dense QCD

Conveners: Derek Teaney (Stony Brook University), Prof. Olga Evdokimov (UIC)

210 Jets and Jet-like Correlations at RHIC

I will present an overview of recent results on jets and jet-like correlation measurements from the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory. Jets are produced in the initial hard scatterings of an event and can therefore be exploited as probes of the hot and dense medium produced in heavy-ion collisions. Previous RHIC results indicate that this medium, the Quark Gluon Plasma (QGP), is strongly coupled, with partonic degrees of freedom. High pT colored partons passing through the sQGP therefore believed to suffer energy loss via induced gluon radiation and elastic collisions, before exiting the medium and fragmenting in vacuum. Jet reconstruction and high pT correlation studies allow us to investigate how the partons interact with the medium and how the medium responds to the partons moving through it. By comparing measurements from p-p and d-Au to those in Au-Au collisions at sqrt(s) = 200 GeV we aim to disentangle cold nuclear matter effects from those of the hot and dense sQGP.

Speaker: Helen Louise Caines (Physics Department-Yale University)

Slides CainesRHIC-JetsDPF.pdf

211 Results from Pb+Pb Collisions with the ATLAS Detector at the LHC

A broad program of measurements using heavy ion collisions is underway in ATLAS, with the aim of studying the properties of QCD matter at high temperatures and densities. This talk describes measurements performed using up to 9 µb-1 of lead-lead collision data provided at a nucleon-nucleon center-of-mass energy of 2.76 GeV by the Large Hadron Collider and collected by the ATLAS Detector during November and December 2010. We will be presenting results on inclusive charged particle multiplicities and elliptic flow to study the global features of the collisions as a function of centrality, pseudorapidity and transverse energy. Higher order Fourier coefficients will also be shown to assess the importance of more complicated event-wise geometric fluctuations. The study of the microscopic properties of the system will be addressed with high pT probes. Muon measurements provide access to W and Z bosons which are potentially sensitive to modifications of the nuclear PDFs, as well as heavy flavor. Charged particle spectra, particularly at high pT, are sensitive to the overall suppression of jets and their modified fragmentation. Finally, jet rates, asymmetries and fragmentation properties offer a more direct look at the physics of jet quenching than has been available at previous facilities.

Speaker: Dr Peter Alan Steinberg (Brookhaven National Laboratory (BNL))

Slides Steinberg_DPF2011_v3.pdf

212 Studies of Jet Quenching in PbPb Collisions at CMS

Jets are an important tool to probe the hot, dense medium which is produced in ultra-relativistic heavy ion collisions. Copious production of hard processes, well above the heavy ion background, occurs at the Large Hadron Collider due to the large increase in collision energy. The multipurpose Compact Muon Solenoid (CMS) detector is well designed to measure the hard scattering processes with its high quality calorimeters and high precision silicon tracker. Jet quenching has been studied in CMS in PbPb collisions at $\sqrt{s_{NN}}=$\,2.76~TeV. As a function of centrality, dijet events with a high pT leading jet were found to have an increasing momentum imbalance that was significantly larger than those predicted by simulations. The angular distribution of jet fragmentation products has been explored by associating charged tracks with the dijets observed in the calorimeters. The calorimeter-based momentum imbalance is reflected in the associated track distributions, which show a softening and widening of the subleading jet fragmentation pattern. Studies of the missing transverse momentum projected on the jet axis have shown that the overall momentum balance can be recovered if tracks at low pT are included. In the PbPb data, but not in the simulations, a large fraction of the balancing momentum is carried by soft particles radiated at large angle relative to the jets.

Speaker: george Stephans (Laboratory for Nuclear Science (LNS)-Massachusetts Inst. of Tec)

Slides Stephans_CMS_HI_jet_DPF_v2.pdf

213 Parton showers as sources of energy-momentum deposition in the QGP and implications for jet observables

I present results on the derivation of the distribution of energy and momentum transmitted from a primary fast parton and its medium-induced bremsstrahlung gluons to a thermalized quark-gluon plasma. The calculation takes into account the important and thus far neglected effects of quantum interference between the resulting color currents. From the result I obtain the rate at which energy is absorbed by the medium as a function of time and find that the rate is modified by the quantum interference between the primary parton and secondary gluons. This Landau-Pomeranchuk-Migdal type interference persists for time scales relevant to heavy ion phenomenology. The newly derived source of energy and momentum deposition is coupled to linearized hydrodynamics to obtain the bulk medium response to realistic parton propagation and splitting in the quark-gluon plasma. Implications for jet observables are discussed.

Speaker: Dr Richard Neufeld (LANL)

Slides sat_qm2011.pdf sat_qm2011.pptx

214 The Wake of a Quark Moving Through Hot QCD Plasma vs. N=4 SYM Plasma

We present the energy density and flux distribution of a quark moving through the high temperature QCD plasma and compare it with that in strongly coupled N=4 SYM plasma. The Boltzmann equation is reformulated as a Fokker-Planck equation at leading log approximation and is solved numerically with non-trivial boundary conditions in momentum space. We use the kinetic theory and take the Fourier transform to calculate the energy and momentum density in real space. The angular distribution exhibits the transition to the ideal hydrodynamics and is analyzed with the first and second order hydrodynamic source. The AdS/CFT correspondence allows the same calculation in strong coupling regime. Compared to the kinetic theory, the energy-momentum tensor is better described by hydrodynamics even after accounting for the differences in the shear viscosities. We argue that the difference between Boltzmann and AdS/CFT comes from the second order hydrodynamic coefficient tau_pi, which is generically large compared to the shear length in a theory based on the Boltzmann equation.

Speaker: JUHEE HONG (Stony Brook University)

Slides wake.pdf

Higgs Physics

Conveners: Dr Laura Reina (Florida State University), Prof. Wade Cameron Fisher (Michigan State University)

215 A Search For The Higgs Boson In H -->Gamma Gamma Mode

We report on a search for SM Higgs Boson in the mode H --> gamma gamma conducted by the CMS experiment with the data accumulated during the 2010 & 2011 running of the LHC at sqrt(s) = 7 TeV.

Speaker: Christopher Allan Palmer (Department of Physics-Univ. of California San Diego (UCSD))

Slides CMS_Hgg_DPF_11Aug2011.pdf

216 A Search For The Higgs Boson In H --> WW

We report on a search for the Higgs boson in the decay mode H --> WW based on data collected by the CMS experiment during the 2010+2011 running of the LHC.

Speaker: Kevin Kai Hong Sung (Massachusetts Inst. of Technology (MIT))

Slides dpftalk.pdf

217 Search For The Standard Model Higgs Boson In The WH->lnubb And H->WW->lnulnu Decay Modes

Results for a Higgs boson search by the ATLAS experiment in the WH->lnubb and H->WW->lnulnu decay modes using a multivariate approach are presented. The results are based on data taken in 2011 at 7 TeV center-of-mass energy. No evidence is found for a Standard Model-like Higgs boson in either decay mode. Exclusion limits in terms of the ratio to expected SM rate are reported in Higgs mass ranges of 115-130 GeV and 120-600 GeV respectively in the two modes.

Speaker: G Carrillo Montoya (Department of Physics-University of Wisconsin)

Slides GD_CARRILLOMONTOYA_HWW.pdf GD_CARRILLOMONTOYA_HWW.pptx

218 Higgs Tansverse Momentum Distributions at the LHC

In this talk I will present a factorization theorem for the Higgs transverse momentum spectrum using SCET (Soft Collinear Effective Theory). This theorem allows us systematically resum large logarithms of $p_T$ in the regime $m_h \gg p_T \gg \Lambda_{QCD}$. The transverse momentum distributions of Higgs produced via gluon fusion will be presented and compared to previous results derived using effective field theory, as well as the results of Collins Soper and Sterman (CSS). The differences will be illuminated. I will also present new results for the Higgs $p_T$ spectrum for b-quark fussion.

Speaker: Dr Jui-Yu Chiu (Carnegie Mellon University)

Slides Chiu_Higgs_PT

219 Updated Search for Standard Model Higgs to WW Production Using up to 8.2 fb-1 at the Tevatron

We report on the search for Standard Model (SM) Higgs boson to WW production in the final state of two charged leptons (e,mu) and two neutrinos from the collision of p-pbar pairs at sqrt(s) = 1.96 TeV. The data corresponds to 8.2 fb-1 by the CDF II detector and 8.2 fb-1 by the DZero detector on the Tevatron collider at Fermilab. The CDF version of the analysis implemented several improvements over the previous versions reported in the spring. In the CDF update, track and calorimeter isolation quantities for the leptons were recalculated to prevent mutual spoilage when two candidates are in close proximity to each other. Additionally, CDF has introduced a likelihood based category for forward electrons to recover candidates failing the original and still present cut based category. To maximize signal acceptance, events with same-sign dileptons and trileptons are included as separate regions to account for associated Higgs production with a Z or W boson via vector boson fusion. Additionally, the CDF analysis includes events with low dilepton invariant mass are included in a separate region to further improve acceptance. We then set confidence level limits at nineteen Higgs masses between 110 GeV and 200 GeV.

Speaker: Benjamin Carls

Slides HWWDPFTalkNew.pdf

220 Searches for Diboson Production in the Lepton + MET + Jets Final State in ATLAS

The study of diboson production at high energy colliders tests the electroweak sector of the standard model (SM) and provides a sensitive probe of new physics beyond the SM. An important example is the production of a Higgs boson with mass greater than 140 GeV/c^2 which decays primarily to W boson pairs. The diboson decay channel where one W boson decays to leptons and the other vector boson decays to quarks leading to high energy jets is particularly interesting due to its large branching fraction as compared to all-leptoninc channels but is also challenging due to large backgrounds, particularly from W+jets. We present searches for diboson production in the lepton + MET+ jets final state using \sqrt(s)=7 TeV collision data collected by the ATLAS detector during the 2011 run. Particular emphasis is placed on searches for (1) the SM Higgs boson with mass above the W pair production threshold and (2) SM WW+WZ production.

Speaker: Mark Neubauer (University of Illinois at Urbana-Champaign)

Slides 360_MarkNeubauer.pdf 360_MarkNeubauer.pptx

221 A Search For An Exotic Higgs In The Decay Mode H++ --> l+l+

We report on a search for a doubly charged Higgs H++ --> l+l+ conducted by the CMS experiment with the data accumulated during the 2010 & 2011 running of the LHC at sqrt(s) = 7 TeV.

Speaker: Maxwell Chertok (Department of Physics-University of California Davis (UCD))

Slides chertok-DPF11-H++.pdf

Low Energy Searches for Physics Beyond the Standard Model

Conveners: Shufang Su (University of Arisona), William Molzon (University of California, Irvine)

222 The COMET Experiment to Search for Muon to Electron Conversion

Speaker: Mark Lancaster (UCL)

Slides 511_MarkLancaster_COMET.pdf

223 The Mu2e Experiment at Fermilab

The goal of the Mu2e experiment is to improve on the existing experimental limits for the neutrinoless conversion of a muon into an electron by four orders of magnitude. Such sensitivity means that if low-energy supersymmetry is discovered at the LHC, Mu2e will provide complimentary information. Even in the absence of new physics at the TeV scale, Mu2e could still find evidence for new physics at mass scales up to 10^4 TeV. In this talk I will give a brief account of the theoretical motivation for the experiment, the current status of the design, planned methods to detect the conversion electron and to suppress backgrounds, and the expected sensitivity of the Mu2e experiment.

Speaker: Prof. Craig Group (University of Virginia)

Slides DPF_2011_Mu2e.pdf DPF_2011_Mu2e.pptx

224 Results from MEG Experiment

Speaker: donato nicolo (pisa university)

Slides nicolo_dpf11.pdf nicolo_dpf11.pptx

225 The Fermilab Muon (g-2) Experiment

Fermilab E989 has the goal to improve on the precision of the muon anomalous magnetic moment, a_mu = (g_mu - 2)/2 by at least a factor of 4 beyond the 0.54~ppm relative precision obtained in E821 at Brookhaven. The precision storage ring will be relocated to Fermilab and installed in a new building. A new 8~GeV/c proton beamline and 3.1~GeV/c muon beamline will be built. The unique capabilities of Fermilab to produce a proton beam with pulses containing ~ 1 X 10^{12} protons at an advantageous duty factor will provide the necessary increase of statistics in a reasonable running time. This new experiment should clarify the apparent > 3 sigma difference between the experimental and Standard-Model values of a_mu.

Speaker: Bradley Lee Roberts (Boston University)

Slides

• 483_BLRoberts-g-2.pdf
• 483_BLRoberts-g-2.pdf
• 483_BLRoberts-g-2.ppt

226 The Enriched Xenon Observatory for double beta decay

The Enriched Xenon Observatory (EXO) is an experimental program designed to search for the neutrinoless double beta decay (0nbb) of Xe-136. Observation of 0nbb would determine an absolute mass scale for neutrinos, prove that neutrinos are massive Majorana particles (indistinguishable from their own antiparticles), and constitute physics beyond the Standard Model. The current phase of the experiment, EXO-200, uses 200 kg of liquid xenon with 80% enrichment in Xe-136, and also serves as a prototype for a future 1-10 ton scale EXO experiment. The double beta decay of xenon is detected in an ultra-low background time projection chamber (TPC) by collecting both the scintillation light and the ionization charge. The detector is now operational at Waste Isolation Pilot Plant (WIPP) in New Mexico. It was first run with natural xenon to fully commission it and study its performance. Preparation for physics data taking is underway. The projected two-year sensitivity for neutrinoless double beta decay half-life is 6.4E25 y at 90% confidence level. In view of a future ton scale experiment, the collaboration is performing R&D to realize an ideal, background-free search for which the daughter nucleus produced by the double beta decay is also individually identified. In this talk, the current status and preliminary results from EXO-200 will be presented, and prospects for a ton scale EXO experiment will be discussed.

Speaker: Timothy Daniels (University of Massachusetts)

Slides 408_timdaniels.pdf

Particle Astrophysics and Cosmology: Chaired by Jocelyn Monroe

Conveners: Jocelyn Monroe (MIT), Dr Scott Dodelson (Fermilab/UChicago)

227 The MiniCLEAN Dark Matter Experiment

The MiniCLEAN dark matter experiment exploits a single-phase liquid argon (LAr) detector, instrumented with photomultiplier tubes submerged in the cryogen with nearly 4pi coverage of a 500 kg (150 kg) target (fiducial) mass. The high light yield and unique properties of the scintillation time-profile in LAr provide effective defense against radioactive backgrounds through pulse-shape discrimination and event position-reconstruction. The detector is also designed for a liquid neon target which, in the event of a positive signal in LAr, will enable an independent verification of backgrounds and provide a unique test of the expected A^2 dependence of the WIMP interaction rate. The conceptually simple design can be scaled to target masses in excess of 10 tons in a relatively straightforward and economic manner. The experimental technique and current status of MiniCLEAN will be summarized.

Speaker: Dr Andrew Hime (Los Alamos National Laboratory)

Slides 144_AndrewHime.pdf

228 The DarkSide Program at LNGS

DarkSide is a direct detection dark matter program based on two-phase argon time projection chambers using argon from underground sources that is naturally depleted in 39Ar. DarkSide-50, the first physics detector in the DarkSide program, will be deployed within the Borexino CTF tank in Gran Sasso Laboratory, Italy. The unique combination of the CTF muon veto, ultra-low background construction techniques, depleted argon, and a dedicated high efficiency neutron veto based on boron-loaded liquid scintillator should give DarkSide-50 the ability to convincingly demonstrate a background expectation of a fraction of an event in a 0.1 tonne-year exposure. This will not only give the experiment the ability to probe for WIMP interactions with a cross-section sensitivity of 10E-45cm2, but also allow it to demonstrate the ability of larger, tonne-scale, detectors in the DarkSide program to operate background free.

Speaker: Alex Wright (Princeton University)

Slides Wright_DPF2011.pdf

229 Constraining Light Dark Matter with CDMS II and SuperCDMS

There has been much recent interest in Weakly Interacting Massive Particle (WIMP) models with masses below 10 GeV/c^2. Data from the Cryogenic Dark Matter Search (CDMS II) have been reanalyzed to give increased sensitivity to these models. Using a lowered, 2 keV recoil energy threshold, we have reanalyzed data from eight germanium detectors operated at the Soudan Underground Laboratory, and used these data to place constraints on light WIMP models. We discuss the compatibility of these results with possible low-mass WIMP signals from the DAMA/LIBRA and CoGeNT experiments, and also discuss prospects for improving SuperCDMS sensitivity to light WIMPs by operating existing detectors in a high-voltage mode.

Speaker: Scott Hertel (Department of Physics)

Slides hertelDPF.pdf

230 Status of the LUX Dark Matter Experiment

The Large Underground Xenon (LUX) experiment will facilitate direct detection of Weakly Interacting Massive Particles (WIMPs) with a 350 kg xenon TPC. LUX will be able to detect 100 GeV WIMPs with scalar cross section as low as 7e−46 cm2, equivalent to ~0.5 events/100 kg/month in a 100 kg inner fiducial volume. Electromagnetic background event rates are limited below 5e−4 events/keV/kg/day by an extensive screening and background modeling program, and assume a conservative 99.5% electron recoil event rejection and 50% nuclear recoil acceptance for WIMP signatures. LUX is currently in the initial deployment phase at the Sanford Surface Laboratory at Homestake, during which all detector hardware and the full electronics chain are being extensively characterized. A miniature water shield reduces ambient electromagnetic backgrounds to rates allowing data taking via radioactive calibration sources. The underground deployment phase will begin in November 2011, with WIMP search data taking beginning shortly thereafter. LUX will surpass all existing dark matter limits for WIMPs with mass above ~10 GeV within days after beginning its science run.

Speaker: Mr Jeremy Chapman (Brown)

Slides LUXDPF_Chapman.pdf LUXDPF_Chapman.ppt

231 Status of CoGeNT

Recent results from CoGeNT and future directions will be discussed.

Speaker: Juan Collar Colmenero (University of Chicago)

Slides CoGeNT.pdf

232 After LUX: The LZ Program

The Large Underground Xenon (LUX) dark matter search experiment is currently being deployed at the Sanford Laboratory at Homestake in South Dakota (see Rick Gaistkell’s talk), as a precursor to DUSEL. In partnership with more international institutions, we are already thinking about the next (two) experiment(s) that will follow: LZ-S (3 t) and LZ-D (20 t). This talk describes the work accomplished to date, the direction we are going, and the expected science schedule.

Speaker: Mr David Malling (Brown University)

Slides 414_LZ_Malling.pdf

Top Quark Physics: Chaired by Nick Kidonakis

Conveners: Reinhard Schwienhorst (Michigan State University), Dr Zack Sullivan (Argonne National Laboratory)

233 HollowConeSieveForTops

The LHC is a top factory: in the SM about 8,000 top pairs should have been produced with more than 47 pb−1 integrated luminosity already taken per detector at 7 TeV. Since the LHC center-of-mass energy is high compared to the top mass, the tops will typically be highly boosted, so that the decay products are close to each other. Thus, in the detector, at first sight, the top decay products may look like a fat jet instead of the several separate ones of which it is composed. In the top reconstruction, to catch all the three main decay products of a top a a single fat jet, it is natural to use a large jet size. If a large R = 1.5 is used, it is likely that two jets will be constructed in the event (one from the top and the other from the t), while more will be constructed using a small R. The light jets behave differently from the top jets, in that the number of reconstructed light jets does not vary with R. So, after subtracting light jets from dijet events, the top contribution can be seen in the variation of the number of jets with cone size R. We develop the “hollow cone ” idea to tag top pairs. Consider the anti-kt algorithm as a “ perfect cone ” algorithm. When a larger cone size is used, both a ttbar event and a QCD dijet event will give two jets, when a smaller cone size is used, a ttbar event will have more jets while a QCD dijet event still have two. This means, for a fat jet with a large cone size, after subtracting a jet of small cone size in the interior, if some jets remain in the hollow cone, the jet is likely to be a top jet, and if there is no jet in the hollow cone, it is likely to be a light quark jet or a gluon jet. Our top tagging algorithm proceeds in the following steps, trying to separate top pairs from the QCD dijet events: 1) Reconstruct jets using the anti-kt jet algorithm with R = 1.5 to obtain a set of jets. The number of jets is njets. 2) Redo the jet reconstruction,with R = 0.6 (or R = 0.7), following recent works of ATLAS and CMS , to obtain another set of jets. 3) Keep the event as a tt candidate if n_{jets,R=1.5} = 2 and n_{R=0.6 }>2 . 4) Go into the 2 jets reconstructed in step 1, find all the subjets for each fat jet, for a fat jet of invariant mass of mj , undo the last step of jet clustering to obtain two jets j1 and j2, with invariant masses mj1 and mj2 ( mj1 > mj2 ). If mj1 <0.9 mj , keep both j1 and j2, otherwise, keep only j1 to add to the subjet list and decompose further. Add ji to the jet substructure list if mji < 30 GeV, otherwise decompose ji iteratively. If the total number of subjets is less than 4, reject the event, because a hadronic top and one semileptonic top should give 4 subjets in total, and two hadronic tops will result in 6 subjets. 5) See whether there is a W inside either of the 2 fat jets, if not, reject the event. To do this, look into a fat jet and iterate over all of the 2 subjets configurations. After the jet filtering, if the invariant mass of the 2 subjes falls in the window of 65 GeV to 95 GeV, tag that configuration as a W. 6） See whether either of the two jets has a subjet can be tagged as a b jet. The jet candidates of a W must not be tagged as a b-jet. Keep other b-tagged events. 7)Any event that survives the above sequence is tagged as a tt event. Backgrounds: The main backgrounds are Wbbbar and Z bbbar. Since there will be b jets in both cases, and the Z mass is close to W mass, these two backgrounds are indistinguishable in their hadronic decay channels. Other backgrounds are the QCD dijets from light quarks and gluons and QCD multi-jet events. QCD dijets events will be gotten rid of by the “ hollow cone ” cut, since the anti-kt jet algorithm is collinear and infrared safe. QCD trijet events will be eliminated by requiring 4 or more subjets. With fake b-jets, Wjj and Zjj events contribute to the background also.we apply the following cuts in sequence : cut 1 : The “hollow cone” sieve. Require njets = 2 and nveto > 2. cut 2 : Total number of subjets >=4. cut 3 : A hadronic W can be tagged. cut 4 : A b jet can be tagged. After the cut, ttbar is 4.05 pb, Wbbbar is down to 0.18, Zbbbar is down to 0.43, Wjj is down to 0.08, Zjj is down to 0.26. The resulting ratio of hadronic tops to semileptonic tops is 2.81, which is consistent with the ratio of decay branching fractions of 3.13. The transverse momentum distribution of tagged top shows that the method is picking top jets instead of light jets, and also demonstrates that top jets with relatively low pt can be tagged. Former top tagging techniques require the pT of the top to be harder than 200 GeV.

Speaker: Ms Peisi Huang (Department of Physics-University of Wisconsin-Madison)

Slides top.pdf

234 Search for ttbar Resonances in the Lepton plus Jets Channel in pp Collisions at Sqrt(s)=7 TeV using the ATLAS Detector

Several Beyond the Standard Model (BSM) theories predict the existence of new resonances that decay into ttbar pairs. We describe a search for such resonances using lepton plus jet data collected by the ATLAS experiment in pp collisions at Sqrt(s)=7 TeV. The selection criteria and search method are presented. In the absence of signal, we produce 95% CL limits on the production cross section times branching ratio of resonances predicted by a few such BSM models.

Speaker: Venkatesh Kaushik (University Of Arizona)

Slides ttbar.res.venkat.2011-08-10.dpf2011.pdf

235 Discriminating Top-Antitop Resonances using Azimuthal Decay Correlations

Top-antitop pairs produced in the decay of a new heavy resonance will exhibit spin correlations that contain valuable coupling information. When the tops decay, these correlations imprint themselves on the angular patterns of the final quarks and leptons. I will discuss how to probe the structure of a resonance's couplings to tops by measuring the azimuthal angles of the tops' decay products about the production axis. These angles exhibit modulations from helicity interference which are typically O(0.1-1), and which by themselves allow for discrimination of spin-0 from higher spins, measurement of the CP-phase for spin-0, and measurement of the vector/axial composition for spins 1 and 2. For relativistic tops, the azimuthal decay angles can be well-approximated without detailed knowledge of the tops' velocities, and appear to be robust against imperfect energy measurements and neutrino reconstructions. I will illustrate this point in the highly challenging dileptonic decay mode, which also exhibits the largest modulations. I will comment on the relevance of these observables for testing axigluon-like models that explain the top quark $A_{FB}$ anomaly at the Tevatron, through direct production at the LHC.

Speaker: Brock Tweedie (Boston University)

Slides Tweedie_DPF.pdf

236 Measurement of the top pair invariant mass distribution at 7 TeV and search for New Physics

We present a measurement of the top-pair mass in tt events by using proton-proton collisions at the LHC at a centre-of-mass energy of 7 TeV. We use data collected with the CMS experiment during the year 2011. The analysis is performed in all possible final states originating from top-pair production, and the full event reconstruction is performed by using different reconstruction methods according to the final state under consideration. The measurement is then used for searching for production of a massive, narrow-width, neutral boson decaying into top-pairs. We observe no significant deviations from the QCD expectations, therefore we translate the measurement into an upper limit on the new physics production cross-section as a function of the particle mass.

Speaker: Salvatore Rappoccio (Department of Physics and Astronomy-Johns Hopkins University (J)

Slides rappoccio_dpf2011.pdf

237 Measurements of spin correlation in $\boldsymbol{t\bar{t}}$ production at D0

We measure the correlation between the spin of the top quark and the spin of the anti-top quark in $t\bar{t} \rightarrow W^{+}bW^{-}\bar{b}$ final states produced in $p\bar{p}$ collisions at a center of mass energy $\sqrt{s}=1.96$~TeV, using data collected with the D0 detector at the Fermilab Tevatron collider. The correlation is extracted using a double differential angular distribution and a novel technique using matrix element integration is used to increase the sensitivity of the result, Measurements are performed in both the dilepton and lepton+jets final states.

Speaker: Kenneth Bloom (Department of Physics and Astronomy-University of Nebraska)

Slides dpf_spincorr_110810.pdf

Thursday, August 11

8:00 AM Breakfast

Plenary Session

Convener: Savvas Koushiappas (Brown University)

238 High Energy Gamma-Ray and Neutrino Astrophysics

Speaker: John Beacom (Ohio State University)

Slides DPF11.pdf

239 Early Universe and Cosmology

Speaker: Mark Trodden (University of Pennsylvania)

Slides Trodden-dpf2011.pdf

240 Dark Matter Searches

Speaker: Jonghee Yoo (FNAL)

Slides YooDPF2011.key.pdf

10:00 AM Coffee

Accelerator Physics

Conveners: R. Joel England (SLAC), Dr Vladimir Shiltsev (Fermilab)

241 MICE step I: first measurement of emittance with particle physics detectors

The muon ionization cooling experiment (MICE) is a strategic R&D project intending to demonstrate the only practical solution to prepare high brilliance beams necessary for a neutrino factory or muon colliders. MICE is under development at the Rutherford Appleton Laboratory (UK). It comprises a dedicated beam line to generate a range of input emittance and momentum, with time-of-flight and Cherenkov detectors to ensure a pure muon beam. The emittance of the incoming beam is measured in the upstream magnetic spectrometer with a sci-fiber tracker. A cooling cell will then follow, alternating energy loss in Li-H absorbers and RF acceleration. A second spectrometer identical to the first and a second muon identification system measure the outgoing emittance. In the 2010 run the beam and most detectors have been fully commissioned and a first measurement of the emittance of a beam with particle physics (time-of-flight) detectors has been performed. The analysis of these data should be completed by the time of the Conference. The next steps of more precise measurements, of emittance and emittance reduction (cooling), that will follow in 2011 and later, will also be outlined.

Speaker: Ulisse Bravar

Slides Recovered_File_22.pdf

242 Precision Calibration of the Luminosity Measurement in ATLAS

A precision luminosity measurement is of critical importance for the ATLAS physics program, both for searches for new physics as well as for precision measurements of Standard Model cross-sections. The calibration of the luminosity is based on three so-called van der Meer scans that were performed in 2010. These scans determine the convolved beam sizes in the vertical and horizontal directions, and together with precise knowledge of the beam currents are used to determine an absolute luminosity scale. Based on this analysis ATLAS has determined the luminosity with a total uncertainty of 3.4% for the 2010 data recorded at root(s) = 7 TeV.

Speaker: Eric Torrence (University of Oregon)

Slides lumiTalk.pdf

243 Novel Accelerator Methods and Technologies for KEKB Upgrade

The KEKB B factory is being upgraded to search for physics beyond the Standard Model, with a target luminosity of 8x10^35 cm^-2 s^-1, a factor of 40 times greater than the world record luminosity achieved at KEKB. To achieve this target luminosity the upgraded machine, SuperKEKB, will require the use of new advances in accelerator technology, among them the development of a low-emittance, high-bunch-charge injector system, a high-beam-current vacuum system incorporating the latest electron-cloud mitigation techniques, an interaction region design that provides a low beta function at the collision point while minimizing emittance growth due to fringe fields and maximizing the dynamic aperture, and beam diagnostics and feedback for monitoring and controlling low-emittance beams and their collisions. This talk will discuss the design challenges facing SuperKEKB, and the technologies that are being developed to meet them.

Speaker: Dr John Flanagan (KEK)

movie tunnelquakemovie.wmv

Slides flanagan_dpf2011.pdf flanagan_dpf2011.pptx

Beyond the Standard Model

Convener: Dr Ariel Schwartzman (SLAC)

244 Supersymmetric multiple Higgs doublet models

The minimal supersymmetric standard model (MSSM) is extended by the inclusion of an addition pair of constrained Higgs doublet superfields through which the electroweak symmetry breaking is nonlinearly realized. The superpotential coupling to the MSSM Higgs doublet then generates its vacuum expectation value. The resultant Higgs scalars and Higgsino-gaugino mass spectrum is presented for several choices of SUSY breaking and Higgs superpotential mass parameters and the results are contrasted with those of the MSSM.

Speaker: Sherwin Love (purdue university)

Slides 151.pdf

245 Collider Phenomenology of the E6SSM

We consider collider signatures of the exceptional supersymmetric standard model (E6SSM). This model is based on the SM gauge group together with an extra U(1)_{N} gauge symmetry under which right--handed neutrinos have zero charge. To ensure anomaly cancellation and gauge coupling unification the low energy matter content of the E6SSM involve three 27 representations of E_6 and a pair of SU(2) doublets from additional 27 and \bar{27}. Thus E6SSM predicts Z' boson and extra matter beyond the MSSM. In particular, the low--energy spectrum of the E6SSM involves three families of Higgs--like doublets, three families of exotic quarks and three SM singlets that carry U(1)_{N} charges. The E6SSM Higgs sector contains one family of the Higgs--like doublets and one SM singlet that develop vacuum expectation values (VEVs) breaking gauge symmetry. The fermionic and bosonic components of other Higgs--like and singlet superfields form Inert neutralino and chargino states and Inert Higgs states respectively. Two lightest Inert neutralinos tend to be the lightest and next-to-lightest SUSY particles (LSP and NLSP).We analyse the Higgs sector, examine the spectrum and couplings of the Inert neutralinos and charginos and study cosmological implications of the E6SSM. The SM-like Higgs boson can be significantly heavier in the E6SSM than in the MSSM and NMSSM. The model can account for the dark matter relic abundance if the lightest Inert neutralino has mass close to half the Z mass. In this case the SM-like Higgs boson decays more than 95% of the time into either LSPs or NLSPs. This scenario also predicts other light Inert chargino and neutralino states below 200 GeV, and large LSP direct detection cross-sections which is on the edge of observability of XENON100. We also examine the production of the Z' and exotic quarks at the LHC. Since exotic quarks in the E6SSM can be either diquarks or leptoquarks they may provide spectacular new physics signals at the LHC.

Speaker: Roman Nevzorov (University of Hawaii)

Slides e6ssm-dpf-2011.pdf

246 Detecting Fourth Generation Heavy Quarks at the LHC

In this talk, I will discuss the production of fourth generation quarks at the LHC. In particular, if such a quark has a mass in the phenomenologically interesting range of 400GeV-600 GeV and decays to a light quark and a W-boson, I will consider a number of possible signals through which it might be detected. In general, the signals I consider include missing momentum together with jets and either a single high-Pt lepton, an opposite sign pair of high-Pt leptons or a same sign pair of high-Pt leptons. In each case I will discuss methods for separating the signal from the three generation Standard Model background. I will show that these methods should allow the detection of heavy fourth generation quarks for a wide range of quark mass and mixing rates.

Speaker: Dr David Atwood (Iowa State University)

Slides ATWOOD_183_DetctingFourthGeneration_1.pdf ATWOOD_183_DetctingFourthGeneration_1.pptx

247 Higgs Production through Top-prime decays at the LHC

We explore LHC signatures of vectorlike quarks, which are hypothetical fermions whose left- and right-handed components have the same electroweak quantum numbers. We consider interactions of such a quark, top-prime, with the top quark via a Yukawa coupling and with a bottom quark through a $W$ boson. We look at Higgs production through the decay of the top-prime in a top-prime pair production channel through QCD at the LHC with $\sqrt{s} = $ 7 TeV. Such a process depends only on the top-prime mass. In this channel, we consider semi-leptonic $W$-boson decays. This choice is dictated by the reduction of QCD background and a higher cross section than the corresponding much cleaner di-leptonic channel. We suggest a background discrimination strategy involving $b$-tagging and a lepton in the final state. The possibility of the top-prime decaying into a light (120 GeV/$c^2$) and a relatively heavier Higgs (150 GeV/$c^2$) will be explored. The mixing angle between the top and the top-prime, which is a parameter of the model, has been chosen judiciously so that the analysis remains as model independent as possible.

Speaker: Ms Saptaparna Bhattacharya (Brown University)

Slides topprime.pdf

248 Charged X Production in Simplest Higgs via Gauge Boson Fusion

The Simplest Higgs model is one of several Little Higgs extensions that attempt to address the hierchy problem through expansion of the Standard Model weak sector. New charged and neutral weak gauge bosons can cancel out the quadratic Higgs divergences in the Higg’s potential through loop diagrams. Production of charged X gauge bosons is studied through gauge boson fusion in pp collisions at 7 through 14 TeV. The pp > qqW±Y>qQX± production method of X± gauge bosons is shown to produce cross-sections that could be large enough to be detectable at the LHC. Here Q represents new heavy quarks that come out of the Simplest Higgs model, and Y is a massive neutral boson. Possible decay products of these gauge bosons are also discussed.

Speaker: Mr Matthew Bishara (University of Rochester)

Slides DPFAug2011.pdf DPFAug2011.ppt

CP-Violation

Conveners: Enrico Lunghi (Indiana University), Jim Olsen (Princeton University)

249 First ADS Analysis of B+ --> D0 K Decays in Hadron Collisions

We report the first measurement of branching fractions and CP-violating asymmetries of doubly-Cabibbo suppressed B+ --> D0 K decays in hadron collisions, using the approach proposed by Atwood, Dunietz, and Soni (ADS) to determine the CKM angle gamma in 7.0 fb-1 of data. The ADS parameters are determined with accuracy comparable with B factory measurements.

Speaker: Paola Garosi

Slides Garosi_DPF2011.pdf

250 Recent BABAR results on CP violation in B decays

We report on the study of the decay B+ ->D0(D0bar) K+ where the D0 or D0bar decaying to Kpipi0, with the Atwood Dunietz and Soni (ADS) method. We measure the ratios Rads, R+, and R- that, since the processes B+ -> D0barK+ and B+ -> D0K+ are proportional to Vcb and Vub, respectively, are sensitive to rB and to the weak phase gamma. We also report the results of CP violation studies of B->Dcp pi+pi- and B0->D*D*.

Speaker: Dr Romulus Godang (University of Mississippi)

Slides DPF2011_Godang.pdf

251 Measurements of CP Violation in B Decay at Belle

We present the final measurement of time-dependent CP violation in the neutral B decays into charmonium and a K^0 meson with a large data sample containing 772 million B \bar{B} pairs collected at the Upsilon(4S) resonance with with the Belle detector at the KEKB asymmetric-energy e+e- collider. We also reports the first results on CP violation in the radiative penguin decay B^0->K_S phi gamma and B^0->omega K_S gamma, improved measurements of CP violation in B^0->pi^+ pi^- and B^0\to a_1^+- pi^-+ decays as well as new measurements of B decays to rho^0 rho^0 and pairs of charm mesons.

Speaker: Himansu Sahoo (University of Hawaii)

Slides DPF2011-himansu.pdf

252 Updated Measurement of Charmless B Decays at CDF

We present world-leading results on CP-violating asymmetries and branching fractions of several decay modes of B0, Bs , and Lambda_b hadrons into charmless two-body final states using 6/fb of data collected by the CDF experiment.

Speaker: Benjamin Carls

Slides 292_CharmDPFTalkNewNewRec.pdf

253 A New CP Violating Observable for the LHC

We study a new type of CP violating observable that arises in three body decays. We consider decays that are dominated by an intermediate resonance that can go on shell. In many cases, the decay can occur via two different orderings. The required CP-even phase arises due to the different virtualities of the resonance in the two diagrams corresponding to these orderings. This method can be an important tool for accessing new CP phases at the LHC and future colliders.

Speaker: Joshua Berger (Cornell University)

Slides CP_Violation-DPF.pdf

Computing in HEP

Conveners: Ian Fisk (Fermi National Accelerator Laboratory (FNAL)), Michael Ernst (BNL, ATLAS)

254 An outlook of the user support model to educate the users community at the CMS Experiment

The CMS (Compact Muon Solenoid) experiment is one of the two large general-purpose particle physics detectors built at the LHC (Large Hadron Collider) at CERN in Geneva, Switzerland. In order to meet the challenges of designing and building a detector of the technical complexity of CMS, a globally distributed collaboration has been assembled with different backgrounds, expertise, and experience. An international collaboration of nearly 3500 people from nearly 200 institutes in 40 different countries built and now operates this complex detector. The diverse collaboration combined with a highly distributed computing environment and Petabytes/year of data being collected makes CMS unlike any other High Energy Physics collaborations before. This presents new challenges to educate and bring users, coming from different cultural, linguistics and social backgrounds, up to speed to contribute to the physics analysis. CMS has been able to deal with this new paradigm by deploying a user support structure model that uses collaborative tools to educate and reach out its users via a robust software and computing documentation, a series of hands on tutorials per year facilitating the usage of common physics tools, annual hands-on-learning workshops on physics analysis and user feedback to maintain and improve the CMS specific knowledge base. This talk will describe this model that has proved to be successful compared to its predecessors in other HEP experiments where structured user support was missing and the word of mouth or sitting with experts one-on-one was the only way to learn tools to do physics analysis. To carry out the the user support mission worldwide, an LHC Physics Center ( LPC) was created few years back at Fermilab as a hub for US physicists. The LPC serves as a "brick and mortar" location for physics excellence for the CMS physicists where graduate and postgraduate scientists can find experts in all aspects of data analysis and learn via tutorials, workshops, conferences and gatherings. Following the huge success of LPC, a center at CERN itself called LHC Physics Center at CERN ( LPCC) and Terascale Analysis Center at DESY have been created with similar goals. The CMS user support model would also facilitate in making the non-CMS scientific community learn about CMS physics. A good example of this, is the effort by HEP experiments, including CMS, to focus on data preservation efforts. In order to facilitate its use by the future scientific community, who may want to re-visit our data, and re-analyze it, CMS is evaluating the resources required. A detailed, good quality and well maintained documentation by the user support group about the CMS computing and software may go a long way to help in this endeavor.

Speaker: Prof. Sudhir Malik (University of Nebraska/FNAL)

Slides Malik_DPF2011_CMS_UserSupport.pdf

255 ATLAS data analysis on Grid

In 2010 and 2011 the ATLAS Collaboration at LHC collected a large volume of data and published a number of ground breaking papers. The Grid-based ATLAS distributed computing infrastructure played a crucial role in enabling timely analysis of the data. We will present the architecture and general features of the ATLAS distributed analysis system, and discuss the performance of the system and the underlying Grid infrastructure as an analysis platform. We will also discuss future directions in the evolution of ATLAS distributed analysis aimed at improvement of analysis capabilities, robustness and efficiency of the system.

Speaker: Dr Sergey Panitkin (Department of Physics - Brookhaven National Laboratory (BNL))

Slides dpf_panitkin_v3.pdf

256 CMS Computing: Performance and Outlook

After years of development, the CMS distributed computing system is now in full operation. The LHC continues to set records for instantaneous luminosity, recording data at 300 Hz. Because of the intensity of the beams, there are multiple proton-proton interactions per beam crossing, leading to larger and larger event sizes and processing times. The CMS computing system has responded admirably to these challenges. We will present the present status of the system, describe the recent performance, and discuss the challenges ahead and how we intend to meet them.

Speaker: Kenneth Bloom (Department of Physics and Astronomy-University of Nebraska)

Slides dpf_computing_110811.pdf

257 Persistent Data Layout and Infrastructure for Efficient Selective Retrieval of Event Data in ATLAS

The ATLAS detector [1] at CERN has completed its first full year of recording collisions at 7 TeV, resulting in billions of events and petabytes of data. At these scales, physicists must have the capability to read only the data of interest to their analyses, with the importance of efficient selective access increasing as data taking continues. ATLAS has developed a sophisticated event-level metadata infrastructure (TAG [2]) and supporting I/O framework [3] allowing event selections by explicit specification, by back navigation, and by selection queries to a TAG database via an integrated web interface (iELSSI). These systems and their performance have been reported on elsewhere. The ultimate success of such a system, however, depends significantly upon the efficiency of selective event retrieval. Supporting such retrieval can be challenging, as ATLAS stores its event data in column-wise orientation using ROOT TTrees [4] for a number of reasons, including compression considerations, histogramming use cases, and more. For 2011 data, ATLAS will utilize new capabilities in ROOT to tune the persistent storage layout of event data, and to significantly speed up selective event reading. The new persistent layout strategy and its implications for I/O performance will be presented in this paper. [1] ATLAS Collaboration, ATLAS Detector and Physics Performance Technical Design Report, CERN-LHCC-1999-14 and CERN-LHCC-1999-15. [2] J. Cranshaw et al, “Event selection services in ATLAS”, in J. Phys.: Conf. Ser., vol. 219, 042007, 2010 [3] P. van Gemmeren, D. Malon, “The event data store and I/O framework for the ATLAS experiment at the Large Hadron Collider”, in IEEE International Conference on Cluster Computing and Workshops, 2009, pp.1-8. [4] R. Brun and F. Rademakers, “ROOT – An Object Oriented Data Analysis Framework”, Nucl. Inst. & Meth. in Phys. Rev. A 389 (1997) 81-86. See also http://root.cern.ch

Speaker: Peter Van Gemmeren (Argonne National Laboratory)

Paper Dpf_2011_StorageLayout.docx Dpf_2011_StorageLayout.pdf

Slides Dpf_2011_StorageLayout.pdf Dpf_2011_StorageLayout.pptx

Heavy Flavor Physics: Bs and tau decays

Conveners: Alexey Petrov (Wayne State University), Prof. Christian Bauer (UC Berkeley), Owen Long (University of California Riverside)

258 Searches for Rare and Forbidden B and Charm Decays with BABAR

We present recent BABAR results of searches for rare decays with new physics sensitivity. In particular, we present the results of searches for B -> gammma gamma and the lepton and baryon number violating modes B->Lambda(c)l and B->K/pi tau l. We also describe recent searches for the charm decays D-> Xl+l-, D0 -> gamma gamma and D0->l+l-.

Speaker: Alessandro Rossi (INFN Perugia)

Slides rossi_dpf2011.pdf

259 Bc and Suppressed Bs Decays at CDF

We present new results of CDF measurements of Bc and suppressed Bs decays. The first measurement of the Bc lifetime in an exclusive fully-reconstructed final state is reported. An improved measurement of the Bs->DsDs decay is reported along with a measurement of the branching ratio and lifetime for Bs->J/psif0 decays and the first measurement of a CP violating asymmetry in Bs->phiphi decays.

Speaker: William Wester (Fermi National Accelerator Lab. (Fermilab))

Slides 294_WilliamWester.pdf

260 Updated Measurement of B(Bs -> Ds(*)+Ds(*)-) and Determination of Delta Gamma_CP

Using fully reconstructed $B_{s}$ mesons, we measure the branching fractions for the decays of $B_s \to D_s^{(*)+}D_s^{(*)-}$ exclusively. Assuming these decay modes saturate decays to CP-even final states, the branching fraction determines the relative width difference between the $CP$-odd and $CP$-even $B_s$ states. The results are based on a data sample collected with the Belle detector at the $\Upsilon(5S)$ resonance with an integrated luminosity of 122 fb$^{-1}$ at the KEKB asymmetric-energy $e^+ e^-$ collider.

Speaker: Ms Sevda Esen (University of Cincinnati)

Slides DPF11_v0.3.pdf

261 Measurement of the relative branching fraction of Bs -> J/psi f_0(980), f_0(980) -> pi+pi- to Bs-> J/psi phi, phi -> K+K-

A measurement of the relative branching fraction of $B^0_s\to J/\psi f_0(980)$, $f_0(980)\to\pi^+\pi^-$ to $B^0_s\to J/\psi \phi$, $\phi\to K^+K^-$ is presented. The decay mode $B^0_s\to J/\psi f_0(980)$ is an interesting mode since it is a CP eigenstate and allows the measurement of the CP-violating phase $\phi_s$. Using approximately 8 fb$^{-1}$ of data recorded with the D0 detector at the Fermilab Tevatron Collider, a relative branching fraction of $0.210\pm0.032 (\text{stat}) \pm 0.036 (\text{syst})$ is found.

Speaker: Braden Keim Abbott (Department of Physics and Astronomy-University of Oklahoma)

Slides Abbott_DPF.pdf

262 Three-Pion Decays of the tau Lepton, the a_1(1260) Properties, and the a_1-rho-pi Lagrangian

We show that the a_1-rho-pi Lagrangian is a decisive element for obtaining a good phenomenological description of the three-pion decays of the tau lepton. We choose it in a two-component form with a flexible mixing parameter sin(theta). In addition to the dominant a_1-> rho+pi intermediate states, the a_1-> sigma+pi ones are included. When fitting the three-pion mass spectra, three data sets are explored: (1) ALEPH 2005 pi-pi-pi+ data, (2) ALEPH 2005 pi-pi0pi0 data, and (3) previous two sets combined together and supplemented with the ARGUS 1993, OPAL 1997, and CLEO 2000 data. The corresponding confidence levels are (1) 28.3%, (2) 100%, and (3)7.7%. After the inclusion of the a_1(1640) resonance, the agreement of the model with data greatly improves and the confidence level reaches 100% for each of the three data sets. From the fit to all five experiments [data set (3)] the following parameters of the a_1(1260) are obtained m_{a_1}=(1233+/-18) MeV, Gamma_{a_1}=(431+/-20) MeV. The optimal value of the Lagrangian mixing parameter sin(theta)=0.459+/-0.004 agrees with the value obtained recently from the e+e- annihilation into four pions.

Speaker: Prof. Peter Lichard (Silesian University in Opava)

Slides 306_lichard.pdf

Heavy Ion Physics/Hot and Dense QCD

Conveners: Derek Teaney (Stony Brook University), Prof. Olga Evdokimov (UIC)

263 Gravitational collapse and far from equilibrium dynamics in holographic gauge theories

In recent years holography has emerged as a powerful tool to study non-equilibrium phenomena in certain quantum theories, mapping challenging quantum dynamics onto the classical dynamics of gravitational fields in one higher dimension. One interesting process accessible with holography is the formation of a quark-gluon plasma in strongly coupled non-Abelian gauge theories. In the dual gravitational description, the formation of a quark-gluon plasma maps onto the process of gravitational collapse and black hole formation. I will describe how one can use techniques from numerical relativity to study this process.

Speaker: Paul Chesler (MIT)

Slides Chesler_TALK.pdf

264 Monte-Carlo simulation of jets in heavy-ion collisions

I present recent developments in simulating heavy-ion collisions using a Monte-Carlo event-generator to study high momentum probes. The simulation contains medium effects on the hard probes via the elastic and radiative energy loss and momentum broadening. The lower momentum bulk medium is simulated using relativistic hydrodynamics. Apart from inclusive observables such as the nuclear modification factor, I present results for the dijet asymmetry measured at the Large Hadron Collider, employing state of the art jet reconstruction methods. I demonstrate that Monte-Carlo simulations are an essential tool for connecting fundamental theory to experiments and extracting important information about the properties of the medium created in heavy-ion collisions and its interactions.

Speaker: Dr Bjoern Schenke (BNL)

Slides schenke

265 Effective theory for jets in medium

We revisit the jet broadening and radiative energy loss problems in heavy ion collisions from effective theory point of view. Soft collinear effective theory (SCET) describes the dynamics of QCD at high energies and is particularly suitable for calculations involving jets. By modifying its Lagrangian to include medium interactions we develop an effective theory for jets in medium. A number of issues are addresses in this new language. We demonstrate the gauge invariance of results for jet broadening and radiative energy loss. We show how the cross-section for radiative corrections to jet production factorizes for QCD hard processes. We include the effect of the nuclear recoil in the medium and quantify it for RHIC and LHC energies. Also we calculate the radiative energy loss beyond the conventional soft gluon approximation, extending the previous results to large $x$ values. We discuss the phenomenological applications for RHIC and LHC.

Speaker: Dr grigory ovanesyan (LANL)

Slides DPF_Talk.pdf

266 Transverse Momentum Broadening in Weakly Coupled Quark-Gluon Plasma

Jet quenching parameter or, equivalently, transverse momentum broadening distribution function is an important quantity which helps to understand energy losses in heavy ion collisions and get insights into properties of the de-confined quark-gluon plasma. SCET provides framework to calculate jet quenching parameter at weak coupling using expectation value of two space-like separated light-like Wilson lines which can be evaluated for desired medium. In this work we evaluate transverse momentum broadening distribution function for the quark-gluon plasma in thermal equilibrium using Hard Thermal Loop (HTL) resummed effective thermal field theory and estimate corrections to this approximations.

Speaker: Mr Mindaugas Lekaveckas (MIT)

Slides Lekaveckas.pdf

Higgs Physics

Conveners: Dr Laura Reina (Florida State University), Prof. Wade Cameron Fisher (Michigan State University)

267 Review of recent theoretical developments in Higgs physics

The search for the SM Higgs boson is reaching a critical juncture. Either evidence will be found or an exclusion will be set during the upcoming LHC year of running. We review the recent experimental results and the theoretical progress that has enabled the search for the Higgs.

Speaker: Radja Boughezal (Argonne National Lab.)

Slides DPF2011_boughezal.pdf

268 The Combination of Higgs Searches with the ATLAS Detector

Upper limits on the cross section of Standard Model Higgs boson production at the Large Hadron Collider (LHC) running at a centre-of-mass energy of 7 TeV are determined, based on the searches performed by the ATLAS Collaboration. Models with a fourth generation of heavy leptons and quarks with Standard Model-like couplings to the Higgs boson are also investigated.

Speaker: Haichen Wang (University of Wisconsin-Madison)

Slides 358_HaichenWang.pdf

269 Searches For The Higgs Boson With The CMS Detector

We report on the various SM and BSM Higgs Boson searches conducted by the CMS experiment with the data accumulated during the 2010 & 2011 running of the LHC at sqrt(s) = 7 TeV.

Speaker: Dr Marat Gataullin (Charles C. Lauritsen Lab. of HEPhys-California Institute of Tec)

Slides dpf_higgs_august112011_gataullin_v3.pdf

270 Combined upper limits on Higgs boson production in the Standard Model, fourth generation and fermiophobic models in proton-antiproton collisions at 1.96 TeV at the Tevatron

The combined results from CDF and D0 on direct searches for the standard model (SM) Higgs boson H in ppbar collisions at the Fermilab Tevatron at sqrt(s)=1.96 TeV are presented. Compared to the previous Tevatron Higgs search combination more data have been added, additional new channels have been incorporated, and some previously used channels have been reanalyzed to gain sensitivity. We use the latest parton distribution functions and gluon fusion to Higgs theoretical cross sections when comparing our limits to the SM predictions. In addition to limits on the SM, the results are interpreted in the context of a fermiophobic model in which the diphoton and WW final states are enhanced and also in the context of a model in which the gluon fusion production mode is enhanced by the existence of a fourth generation of fermions. With up to 8.0 fb-1 of data analyzed at CDF and D0, the 95% C.L. upper limits on Higgs boson are calculated.

Speaker: Richard Edward Hughes (Ohio State University)

Slides dpfHiggs.pdf

Neutrino Physics: Chaired by John Beacom

Conveners: , Sam Zeller (FNAL)

271 Neutrino Physics with SciBooNE

SciBooNE (FNAL E954) is designed to measure precise neutrino cross sections on carbon in the one GeV region. Moreover, SciBooNE can serve as a near detector for MiniBooNE neutrino and antineutrino oscillation searches. I will present SciBooNE's most recent results on neutrino cross section measurements and the search for neutrino disappearance with MiniBooNE.

Speaker: Dr Morgan Wascko (Imperial College London)

Slides wascko_20110811.pdf

272 Neutrino interactions in the NOvA near detector prototype

The NuMI Off-Axis electron neutrino Appearance (NOvA) experiment has started taking data with the 209 ton liquid scintillator-filled prototype of the near detector in the end of November 2010. This detector collects data from two sources, the Main Injector complex and from the Booster Neutrino Beam. At the location of the prototype detector due to the off-axis effect the NuMI beam is narrow with maximum around 2GeV. On the other hand the detector is on axis of the BNB beam and sees its maximum around 1GeV. This configuration gives the NOvA experiment a unique opportunity of studying neutrino and anti-neutrino interactions with carbon target from two low energy beams. I will present physics program for the NOvA experiment focusing on the cross section measurements and preliminary data obtained with the near detector prototype.

Speaker: Dr Jaroslaw Nowak (University of Minnesota)

Slides DPF2011_NOVA_XSEC_Nowak.pdf

273 Early Neutrino Data in the NOvA Near Detector

NOvA is a long baseline neutrino experiment using an off-axis neutrino beam produced by the NuMI neutrino beam at Fermilab. The NOVA experiment will study neutrino oscillations from $\nu_{\mu}$ flavor to $\nu_e$ flavor. A short term goal for the NOvA experiment is to develop a good understanding of the response of the detector. These studies are being carried out with the full Near Detector installed on the surface at Fermilab (NDOS). This detector is currently running and will acquire neutrino data for a year. Using beam muon neutrino data, quasi-elastic charge-current interactions will be studied. Status of the NDOS running and early data will be shown.

Speaker: Minerba Betancourt (University of Minnesota)

Slides DPF2011.pdf

274 SciNOvA: A measurement of neutrino-nucleus scattering in a narrow-band beam

SciNOvA is a proposed experiment to deploy a fine-grained scintillator detector in front of the NOvA near detector to collect neutrino-nucleus scattering events in the NUMI, off-axis, narrow-band neutrino beam at Fermilab. This detector can make unique contributions to the measurement of charged- and neutral-current quasi-elastic scattering; and neutral-current $\pi^0$ and photon production. These processes are important to understand for fundamental physics and as backgrounds to measurements of electron neutrino appearance oscillations. The talk will present the strategy and science case of the SciNOvA experiment.

Speaker: Xinchun Tian (Univesrity of South Carolina)

Slides scinova-dpf11.pdf

275 Lorentz noninvariant neutrino oscillations without neutrino masses

The bicycle model of Lorentz noninvariant neutrino oscillations without neutrino masses naturally predicts maximal mixing and a 1/E dependence of the oscillation argument for muon-neutrino to tau-neutrino oscillations of atmospheric and long-baseline neutrinos, but cannot also simultaneously fit the data for solar neutrinos and KamLAND. We search for other possible structures of the effective Hamiltonian for Lorentz noninvariant oscillations without neutrino mass that naturally have 1/E dependence at high neutrino energy. Due to the lack of any evidence for direction dependence, we consider only direction-independent models. Although a number of models are found with 1/E dependence for atmospheric and long-baseline neutrinos, none can also simultaneously fit solar, reactor and short-baseline neutrino data.

Speaker: Prof. Kerry Whisnant (Iowa State University)

Slides kw-dpf11.pdf

276 Three-Parameter Lorentz-Violating Model for Neutrino Oscillations

A three-parameter model of neutrino oscillations is presented. It is based on a simple Lorentz- and CPT-violating texture and is consistent with compelling oscillatory signals and null tests involving atmospheric, accelerator, reactor, and solar neutrinos. The solar and atmospheric mixing angles are fixed by the texture at both low and high energies instead of being independent parameters as in most descriptions. One natural feature of the model is anomalous appearance signals in MiniBooNE at low energies, consistent with recent observations for both neutrinos and antineutrinos. Simple texture-preserving extensions of the model can accommodate the recent MINOS anomaly and the LSND signal.

Speaker: Jorge S Diaz (Indiana University)

Slides DPF2011_JSDiaz.pdf

Particle Astrophysics and Cosmology: Chaired by Andrew Zentner

Conveners: Jocelyn Monroe (MIT), Dr Scott Dodelson (Fermilab/UChicago)

277 The Dark Energy Survey Data Management System

The Dark Energy Survey (DES) is a project with the goal of building, installing and exploiting a new 70 CCD-camera at the Blanco telescope, in order to study the nature of cosmic acceleration. It will cover 5000 square degrees of the southern hemisphere sky and will record the positions and shapes of 300 million galaxies up to redshift 1.4. The survey will be completed using 525 nights during a 5-year period starting in 2012. About O(1 TB) of raw data will be produced every night, including science and calibration images. The DES data management system has been developed for the processing, calibration and archiving of these data. It is being developed by collaborating DES institutions, led by NCSA. In this contribution, we detail how a high performance computing environment is the best choice for this task, what kind of scientific codes are involved and how the Data Challenge process works, to improve simultaneously the Data Management system algorithms and the Science Working Group analysis codes.

Speaker: Mr Ignacio Sevilla (CIEMAT)

Slides DESDM_APS11_ISevilla_final.ppt

278 Studying Cosmic Acceleration with the Dark Energy Survey

The Dark Energy Survey (DES) will use a new massive imaging instrument, the Dark Energy Camera (DECam), to study the properties of the mysterious, presently-dominant source of energy that is causing the universe to go through an accelerating expansion. The camera will be installed on the 4-meter Blanco telescope at the Cerro Tololo Inter-American Observatory and commissioning is expected to start in the end of 2011. Over five years, DES will carry out a high-precision photometric survey of 5000 square degrees to detect and study the properties of over 300 million galaxies in the southern sky. Repeat observations of a smaller patch in the sky will discover thousands of Type Ia supernovae for precision distance measurements. We will describe how the four complementary probes of dark energy -- weak lensing, galaxy clusters, baryon acoustic oscillations, and supernova -- will help improve our understanding of the nature of the mysterious dark energy.

Speaker: Masao Sako (University of Pennsylvania)

Slides 189_DES.pdf 189_DES.pptx

279 The Dark Energy Camera - A new Instrument for the Dark Energy Survey

The Dark Energy Survey (DES) is a next generation optical survey aimed at understanding the expansion rate of the universe using four complementary methods: weak gravitational lensing, galaxy cluster counts, baryon acoustic oscillations, and Type Ia supernovae. To perform the survey, the DES Collaboration is building the Dark Energy Camera (DECam), a 3 square degree, 520 Megapixel CCD camera which will be mounted at the prime focus of the Blanco 4-meter telescope at the Cerro Tololo Inter-American Observatory. The survey will cover 5000 square-degrees of the southern galactic cap with 5 filters (g, r, i, z, Y). DECam will be comprised of 74 250 micron thick fully depleted CCDs: 62 2k x 4k CCDs for imaging and 12 2k x 2k CCDs for guiding and focus. Construction of DECam is nearing completion. In order to verify that the camera meets technical specifications for the Dark Energy Survey and to reduce the time required to commission the instrument on the telescope, we have constructed a full sized ``Telescope Simulator'' and are performing full system testing and integration prior to shipping to CTIO. An overview of the DECam design and the status of the construction and integration tests will be presented

Speaker: Dr Jiangang Hao (Fermilab)

Slides DECam_Hao_DPF2011.pdf

280 Ultra High Energy Cosmology with the POLARBEAR Telescope

Recent studies of the temperature anisotropy of the Cosmic Microwave Background (CMB) lend support to an inflationary origin of the universe, yet no direct evidence verifying inflation exists. Current generation experiments now focus on the polarization anisotropy in the CMB, specifically the curl component of the CMB’s polarization (called the “B-mode”), which is undetected to date. The theory of inflation predicts the existence of a primordial gravitational wave background that imprints a unique signature on the polarization B-mode at large angular scales. The CMB B-mode signal also encodes gravitational lensing information at smaller angular scales, which bears the imprint of large scale cosmological structures. The quest for detection of these signals; each of which is orders of magnitude smaller than the CMB temperature, has motivated the development of background-limited detectors with precise control of systematic effects. The POLARBEAR experiment is designed to perform a d