LHC Ski 2016, Austria

10 Apr 2016, 16:00 → 15 Apr 2016, 14:00 Europe/Zurich

UZ Obergurgl

Christoph Schwanda (Austrian Academy of Sciences (AT)), Jochen Schieck (Austrian Academy of Sciences (AT)), Josef Pradler (Austrian Academy of Sciences (AT)), Wolfgang Adam (HEPHY-Vienna), Wolfgang Waltenberger (HEPHY VIENNA)

This workshop follows the March 2016 Moriond Electroweak session where the first results of the new LHC data at high energy and luminosity are being presented by the experimental collaborations.

The meeting will take place at the University Center Obergurgl, in the ski-resort town Obergurgl located in the upper Ötztal Valley in Tirol, Austria. With 110 km of slopes and an altitude span of 1900m (6200ft) to 3000m (10000ft), excellent winter sports conditions are guaranteed until early May.

Much is at stake when the LHC will explore the Terascale of particle physics with an increased center-of-mass energy of 13 TeV at high luminosity. The Higgs is discovered, but the absence of much anticipated new physics puts severe pressure on what are believed to be our best solutions to the most pressing questions in particle physics: What is the origin of the 16-decade hierarchy between the Planck and Electroweak scale and what is the particle nature of Dark Matter? Is there a natural solution to the hierarchy problem or must we consider embracing the idea that our Universe is just one out of a landscape of possibilities? Finally, will the LHC at higher energies be able to produce Dark Matter in the laboratory and shed light on what 85% of the Universe’s mass is made of?

The aim of the workshop is to bring together key experimentalists and leading particle theorists to “take stock”, discuss the implications of the new data and to devise strategies on how to move forward with the pressing questions mentioned above.

Scientific Advisory Board:

• Peter Graham, Stanford University
• David E. Kaplan, Johns Hopkins University
• Sabine Kraml, LPSC Grenoble
• Paul Langacker, Princeton Institute for Advanced Study
• Thomas Rizzo, Stanford Linear Accelerator Center
• Itay Yavin, Perimeter Institute for Theoretical Physics & McMaster University

Local Organizers:

• Wolfgang Adam (HEPHY)
• Josef Pradler (HEPHY, chair)
• Jochen Schieck (HEPHY, TU Vienna)
• Christoph Schwanda (HEPHY)
• Wolfgang Waltenberger (HEPHY)

Registration is now closed.

LHCSKIBULLETIN.pdf

LHCSki_Timetable.pdf

poster.pdf

Sunday, 10 April

18:30 → 20:00 Dinner

20:00 → 21:00 Opening Talk: the Physics of New Physics

Speaker: Georgi Dvali (NYU and LMU)

21:00 → 22:30 Reception

Convener: Jochen Schieck (Austrian Academy of Sciences (AT))

Monday, 11 April

08:20 → 09:00 The scalar sector of the Standard Model. Moving from discovery to precision physics.

Speaker: Martin Flechl (Austrian Academy of Sciences (AT))

2016-04-11_lhcski_higgs.pdf

09:00 → 09:40 What’s hiding at 750 GeV?

Speaker: Veronica Sanz Gonzalez (University of Sussex)

LHCSKI_Sanz.pdf

09:40 → 10:10 Coffee

10:10 → 10:50 On the Nature of Dynamical Electroweak Symmetry Breaking

Speaker: Francesco Sannino (CP3-Origins)

Sannino LHCSki 2016.pdf

10:50 → 11:30 The stability of the electroweak scale

Speaker: Brian Thomas Batell

Batell-LHCSki.pdf

11:30 → 17:00 Time for discussion, collaboration, and leisure

17:00 → 18:00 MON1

17:00 h(125) boson measurements in ATLAS: run-1 legacy and early run-2 results

This talk will summarize the most important properties of the h(125) boson measured at the LHC run-1 by the ATLAS collaboration. It will also present early measurements made with the first data taken at 13 TeV in 2015.

Speaker: Nicola Venturi (University of Toronto (CA))

H125_ATLAS.pdf

17:20 Studies of Higgs bosons decaying to bosons with CMS

This talk will review the status of what we know about the observed Higgs boson decaying to bosons, together with the search for Physics beyond the standard model in cases with bosons in the final state.

Speaker: Alexei Safonov (Texas A & M University (US))

Higgs_talk_AS.pdf

17:40 Studies of Higgs bosons decaying to fermions with CMS

This talk will review the status of what we know about the observed Higgs boson decaying to fermions, together with the search for Physics beyond the standard model in cases with fermions in the final state. The presentation will cover the couplings from the analyses of final states and initial states like production in association with top quark pairs or single top quarks.

Speaker: Daniel Salerno (Universitaet Zuerich (CH))

160411_HtoFermions_SKI2016.pdf

18:00 → 18:20 Coffee

18:20 → 19:20 MON2

18:20 Induced Electroweak Symmetry Breaking and the Composite Twin Higgs

Induced electroweak symmetry breaking is an alternative to the Standard Model mechanism for triggering the Higgs vev which can preserve a Standard-Model-like Higgs decoupled from additional states. In composite Higgs models, this provides a natural mechanism to explain a hierarchy $v \ll f$ between the EWSB scale and the global symmetry breaking scale. In particular, we describe how composite twin Higgs models with minimal tuning can be realized with this mechanism. A unique feature of this model is the presence of both lower and *upper* bounds on the composite global symmetry breaking scales $\sim 700$ GeV $ \lt f \lt \sim 2$ TeV.

Speaker: Dr Kiel Howe (Fermi National Accelerator Laboratory)

pNGBHiggsTadpole_LHCSKI_4-11-16.key.zip

pNGBHiggsTadpole_LHCSKI_4-11-16.pdf

18:40 Minimal Composite Dynamics versus Axion Origin of the Diphoton excess

ATLAS and CMS observe deviations from the expected background in the diphoton invariant mass searches of new resonances around 750 GeV. We show that a simple realization in terms of a new pseudoscalar state can accommodate the observations. The model leads to further footprints that can be soon observed. The new state can be interpreted both as an axion or as a highly natural composite state stemming from minimal models of dynamical electroweak symmetry breaking. We further show how to disentangle the two scenarios.

Speaker: Dr Emiliano Molinaro (CP3-Origins, University of Southern Denmark)

Molinaro LHC SKI 2016.pdf

19:00 Making sense of the LHC diboson and diphoton excesses

Towards the end of Run-1 data taking, an excess in the diboson as well as eejj channel was announced. During the first round of Run-2 data taking, an excess in diphoton channel has been announced. I consider possible explanations of these excesses in two different BSM scenarios. I demonstrate the feasibility of accommodating the diboson and eejj excess in a Left-Right Symmetric Standard Model. For the diphoton excess, I scrutinise a simplified model with scalar resonance coupling to gluons, photons and fermionic dark matter. I illustrate the monojet constraints on such a simplified model scenario and inspect the possibility of reconsiling the diphoton excess with dark matter constraints.

Speaker: Suchita Kulkarni (Austrian Academy of Sciences (AT))

Kulkarni_LHCSki.pdf

Kulkarni_LHCSki.pdf

Kulkarni_LHCSki.pdf

Tuesday, 12 April

08:20 → 09:00 Low-scale SUSY: RIP or resurrection?

Speaker: Sezen Sekmen (Kyungpook National University (KR))

SekmenLHCSkiSUSYRIPRes160412.pdf

09:00 → 09:40 Fine-tuning sweet spots

Speaker: Maurizio Pierini (CERN)

Pierini.pdf

09:40 → 10:10 Coffee

10:10 → 10:50 "Exotica"? Speaking up for minorities.

Speaker: Tetiana Hryn'ova (Centre National de la Recherche Scientifique (FR))

Exotica-final.pdf

Exotica-final.pptx

10:50 → 11:30 Finding New Physics by understanding Standard Model Processes

Speaker: Christian Schwanenberger (Deutsches Elektronen-Synchrotron (DE))

Searches_Precision_CS.pdf

11:30 → 17:00 Time for discussion, collaboration, and leisure

17:00 → 18:00 TUE1

17:00 Searches for Beyond-Standard-Model Higgs bosons in ATLAS

This talk will briefly summarize the searches for BSM Higgs Bosons performed at the LHC run-1 by the ATLAS collaboration. Then it will present the searches for high mass Higgses in several channels, made at 13 TeV with the 2015 data.

Speaker: Zinonas Zinonos (Georg-August-Universitaet Goettingen (DE))

LHCSki2016-Searches_for_Beyond-Standard-Model_Higgs_bosons_in_ATLAS.pdf

17:20 Highlights of searches for new physics (non-SUSY) with CMS

The Large Hadron Collider has restarted pp collisions at 13 TeV center of mass energy in June 2015. The CMS experiments have taken data at this new energy which allows greater reach in probing for physics beyond the Standard Model. Several results on searches for physics not associated with supersymmetric extensions of the Standard Model are presented. To give few examples, these extensions predict the existence of new massive resonances, contact interactions with non-resonant phenomena, and long-lived particles.

Speaker: Nikoloz Skhirtladze (Kansas State University (US))

skhirtladze_lhcski2016.pdf

17:40 Searches for supersymmetry at CMS in leptonic final states with 13 TeV Data

The CMS SUSY program is very active in performing searches with the 13 TeV data including multiple analyses done in regions with leptonic final states. The results of these analyses are used to expand the reach of the searches done by CMS at 8 TeV and additionally to investigate two excesses seen in run I, namely a 2.6 sigma excess seen by CMS and a 3.0 sigma excess seen by ATLAS. These excesses were observed in two separate signal regions both having final states of at least 2 opposite sign same flavor leptons, jets, and MET.

Speaker: Charles Vincent Welke (Univ. of California San Diego (US))

LHCSKI2016_LeptonicSUSYATCMS.pdf

18:00 → 18:20 Coffee

18:20 → 19:00 TUE2

18:20 Searches for new physics with fermions or jets at the ATLAS detector in LHC Run 2

Many extensions of the Standard Model of particle physics predict heavy new particles and new phenomena, leading to characteristic signatures such as a narrow peak or excess in the tail of distributions. This talk highlights results on searches with fermionic signatures, mainly with high-pT jets and leptons, using 2015 data collected at 13 TeV.

Speaker: Jeff Dandoy (University of Chicago (US))

JeffDandoy_LHCSki_12042016.pdf

18:40 Searches for new physics with bosons at the ATLAS detector in LHC Run 2

Searches for new physics beyond the Standard Model with bosonic signatures in LHC Run 2 are presented. These include searches for resonant production of two massive bosons (VV, VH and HH) and (non)resonant production of photons in high-mass region.

Speaker: Kalliopi Iordanidou (Columbia University (US))

LHCSki2016_IordanidouK.pdf

19:00 → 19:40 Young Scientists Forum 2

19:00 Search for New Physics in Z+MET channel at CMS

Despite the great understanding of particle interactions in terms of the Standard Model and the recent discovery of the Higgs boson at the LHC, the Standard Model of particle physics can not yet explain various phenomena, such as neutrino masses or the Dark Matter halo in the galaxies. This talk presents new LHC Run II results of a search for New Physics in Z+MET channel, discussing the main experimental features along the uncertainties and finally giving an outlook for the future data in Run II.

Speaker: Michael Brodski (Rheinisch-Westfaelische Tech. Hoch. (DE))

Brodski Ski2016.pdf

19:10 Searches for new physics in jet final states in ATLAS at LHC Run II

Significant increase of the center-of-mass energy from 8 to 13 TeV at LHC Run II offers a great discovery potential for new physics at high mass, especially for strongly produced high-mass resources, contact interactions and TeV-gravity phenomena with high-pT jets. This talk presents most recent Run II results from ATLAS on new physics searches in the jet final states.

Speaker: Brian Thomas Amadio (Lawrence Berkeley National Lab. (US))

19:20 New CMS results for H->4l at 13 TeV

This talk will present the H->4l analysis with 13 TeV data, and the corresponding results.

Speaker: Muhammad Bilal Kiani (Universita e INFN Torino (IT))

H->ZZ.pdf

19:30 Constraining composite Higgs models with direct and indirect searches

Direct searches for fermion and vector boson resonances, as well as indirect constraints from precision measurements are both important tools to test the predictions of composite Higgs models. A novel numerical technique allows us to take into account many direct and indirect constraints in a single framework. This talk present results from applying our method to a class of four-dimensional pseudo-Nambu-Goldstone boson Higgs models.

Speaker: Peter Stangl (Excellence Cluster Universe, Munich)

Stangl_1604_LHCski.pdf

Wednesday, 13 April

08:20 → 09:00 Dark Matter Direct Detection in the next 5 years

Speaker: Marc Schumann (University of Bern)

lhcski_schumann_.pdf

09:00 → 09:40 Going Beyond WIMPs: Exploring Light Dark Matter

Speaker: Tomer Volansky (Tel Aviv University (IL))

LHCSki.DMTheoryDetection.2016.1.pdf

09:40 → 10:10 Coffee

10:10 → 10:50 New avenues to search for Dark Matter

Speaker: Maxim Pospelov

Obergurgl2016_pospelov.pdf

10:50 → 11:30 DM at 13 TeV and Data Interpretation

Speaker: David Salek (Nikhef National institute for subatomic physics (NL))

LHCSki_salek.pdf

11:30 → 12:10 Seeking Evidence for Dark Matter in Indirect Detection

Speaker: Olaf Reimer

Obergurgl Indirect DM public.pdf

12:10 → 17:00 Time for discussion, collaboration, and leisure

17:00 → 17:40 New signatures of DM at the LHC

Speaker: Joachim Kopp (Johannes-Gutenberg-Universitaet Mainz (DE))

dm-at-lhc.pdf

17:40 → 18:00 WED1

17:40 How (not) to use simplified models to search for dark matter at the LHC

I will discuss the motivation, the advantages and the problems of using simplified models as a tool to interpret LHC searches for dark matter. I will present a few examples for how this approach can be used to understand the complementarity of different dark matter search strategies. Finally, I will focus on various consistency conditions that should be imposed even on the most simplified models. These conditions can imply the presence of additional new particles and interactions that may change the phenomenology of the model in important ways.

Speaker: Dr Felix Kahlhoefer (DESY)

LHCSKI.pdf

18:00 → 18:20 Coffee

18:20 → 20:00 WED2

18:20 Baryonic Dark Matter at the LHC

I present an extension of the Standard Model where baryon number is a local gauge symmetry that is spontaneously broken. In such a setup, anomaly cancellation requires the introduction of new fermion fields, the lightest of which is an attractive dark matter candidate. Dark matter stability is an automatic consequence of the gauge symmetry, and proton decay never occurs even if baryon number is broken at the low scale. I discuss collider signatures of this model as well as implications for direct and indirect dark matter searches.

Speaker: Michael Duerr (DESY)

LHCSki2016_duerr.pdf

18:40 Dark matter searches from the ATLAS experiment at LHC Run 2

Signatures of large missing transverse momentum recoiling against jets at the LHC provide powerful probe to strongly produced dark matter (DM), complementary to direct and indirect DM detection experiments. This talk presents recent results on dark matter searches with the ATLAS detector in LHC Run 2, focusing on signatures with jets, photons or hadronically decaying bosons.

Speaker: Dan Levin (University of Michigan (US))

19:00 Dark matter searches with CMS

The existence of dark matter, indicated by astronomical observations, is one of the main proofs of physics beyond the standard model. Despite its abundance, dark matter has not been directly observed yet. This talk presents several searches for dark matter production in proton-proton collisions at 7, 8, and 13 TeV at the LHC, performed by the CMS collaboration. They are interpreted in terms of simplified models with different structures and mediators, as well as generic effective theory terms.

Speaker: Manfred Jeitler (Austrian Academy of Sciences (AT))

Jeitler_DM_CMS.pdf

Thursday, 14 April

08:20 → 09:00 Physics Prospects at Future Colliders

Speaker: Jenny List (Deutsches Elektronen-Synchrotron Hamburg and Zeuthen (DE))

jlist_lhcski16.pdf

09:00 → 09:40 CP violation in the Standard Model

Speaker: Jernej F. Kamenik (Jozef Stefan Institute)

Kamenik_LHCSki2016_2.pdf

09:40 → 10:10 Coffee

10:10 → 10:50 Precision Measurements

Speaker: Timothy Gershon (University of Warwick (GB))

gershon-LHCski2016.pdf

10:50 → 11:30 New Physics in the flavor sector

Speaker: Andreas Crivellin (CERN)

LHCski2016.pdf

LHCski2016.ppt

11:30 → 12:10 Physics program at Belle-II in light of LHCb

Speaker: Florian Urs Bernlochner (Universitaet Bonn (DE))

Talk.pdf

12:10 → 17:00 Time for discussion, collaboration, and leisure

17:00 → 18:00 THU1

17:00 A new class of family non-universal Z' models

Recent anomalies in B meson decays observed by the LHCb collaboration have motivated the construction of extensions of the Standard Model with a gauged family non-universal U(1) factor. I will present a large class of family non-universal U(1) gauge models for which flavor changing neutral currents are completely controlled by CKM matrix elements. I will discuss then phenomenological implications of these models, including the possibility to explain the LHCb anomalies.

Speaker: Alejandro Celis (Ludwig Maximilian University of Munich)

celis.pdf

17:20 Muon g-2 in Two-Higgs-Doublet Models

Updating various theoretical and experimental constraints on the four different types of two-Higgs-doublet models (2HDMs), we find that only the ``lepton-specific" (or ``type X") 2HDM can explain the present muon g−2 anomaly in the parameter region of large tanβ, a light CP-odd boson, and heavier CP-even and charged bosons which are almost degenerate. The severe constraints on the models come mainly from the consideration of vacuum stability and perturbativity, the electroweak precision data, the b-quark observables like Bs→μμ, the precision measurements of the lepton universality as well as the 125 GeV boson property observed at the LHC. We also discuss the tau-rich signatures at the LHC to probe the allowed parameter space of Type X 2HDM.

Speaker: Eung Jin Chun (Korea Institute for Advanced Study)

160414-LHCSki-2HDMg-2.pdf

17:40 Status and perspectives with exotic states at LHCb

The analysis of the full LHC Run I data set of proton-proton collision events collected with the LHCb detector, corresponding to an integrated luminosity of 3.0 fb-1, is yielding several improved results on exotic hadron candidates, such as $X(3872)$ and $Z(4430)^+$, as well as the first observation of two new states compatible with the pentaquark hypothesis. Run II data allow LHCb to further sharpen the experimental picture, opening up the possibility to observe new states. The measurements of the properties of these exotic states and the Run II prospects will be presented, including the determination of their quantum numbers, with model dependent and independent methods.

Speaker: Mr Antonio Augusto Alves Junior (University of Cincinnati (US))

talk_Ski2016.pdf

18:00 → 18:20 Coffee

18:20 → 19:00 THU2

18:20 Belle II studies of missing energy decays and searches for dark photon production

The Belle II experiment at the SuperKEKB collider is a major upgrade of the KEK B factory in Tsukuba, Japan. The machine is designed for an instantaneous luminosity of $8\times 10^{35}$ cm$^{-2}$s$^{-1}$ and the experiment is expected to accumulate a data sample of about 50 ab$^{-1}$ in 5 years running. With this amount of data, decays sensitive to physics beyond the Standard Model can be studied with unprecedented precision. One promising set of modes are physics processes with missing energy such as $B\to\tau\nu$, $B\to D^{(*)}\tau\nu$ and $B\to K^{(*)}\nu\bar\nu$. The Belle II data also allows searches for the dark photon, the gauge mediator of a hypothetical dark sector, which recently received much attention in the context of dark matter models.

Speaker: Luigi Li Gioi (Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut) (D)

LHCSKI_2016_LLG.pdf

18:40 LHCb measurements at 13 TeV with online data analysis exploiting new trigger and real time alignment and calibration

By using the very first proton-proton collision data of the LHC Run II, LHCb performed a series of measurements, notably including the cross-sections for quarkonia, beauty and charm productions. The results have been carried out by exploiting a new scheme for the LHCb software trigger, where the algorithm has been split in two stages to allowing for a delayed trigger decision. This enables the alignment and calibration to be performed in real time, hence achieving an optimal reconstruction performance already at the trigger level. In turn this gives the possibility to finalise physics analyses directly from data objects produced by the online reconstruction. Physics results will be discussed with some emphasis on the performance and technical implementation of this novel trigger approach.

Speaker: Barbara Storaci (Universitaet Zuerich (CH))

Storaci_LHCSki2016.pdf

19:00 → 19:40 Young Scientists Forum 4

19:00 Low Scale Unification @ LHC

The Talk is based on - P. Fileviez Perez, S. Ohmer and H. H. Patel, "Minimal Theory for Lepto-Baryons", Phys.Lett. B735 (2014) 283-287, [arXiv: 1403.8029] - P. Fileviez Perez and S. Ohmer, "Low Scale Unification of Gauge Interactions", Phys.Rev. D90 (2014) 3, 037701, [arXiv: 1405.1199] - S. Ohmer and H. H. Patel, "Leptobaryons as Majorana Dark Matter", Phys.Rev. D92 (2015) 5, 055020, [arXiv: 1506.00954]

Speaker: Sebastian Ohmer (Max-Planck-Institut fuer Kernphysik (MPIK), Heidelberg)

Ohmer_LowScaleUnificationLHC_LHCSki.pdf

19:10 Angular analysis of B → K(∗)l+l− at the Belle experiment

We present the measurement of angular observables in the decay $B^0\to K^{∗0}(892)\ell^+\ell^−$, where $\ell^+\ell^−$ is either $e^+e^−$ or $\mu^+\mu^−$. The analysis is performed on a data sample corre- sponding to 711 fb$^{−1}$ containing $772 × 10^6$ $B\bar B$ pairs, collected at the $\Upsilon(4S)$ resonance with the Belle detector at the asymmetric-energy $e^+e^−$ collider KEKB. Four form-factor independent angular observables and the longitudinal polarization of the $K^{∗0}(892)$, $F_L$ and the transverse polarization asymmetry $A(2)$ are extracted in five bins of the invariant mass squared of the lepton system $q^2$. We compare our results in the region $q^2 < 8$ GeV$^2$/$c^4$ with Standard Model predictions and analyze the $q^2$ region in which the LHCb collaboration reported the so called $P_5′$ anomaly [1, 2]. References [1] Aaij, R and others Measurement of Form-Factor-Independent Observables in the Decay $B^0\to K^{∗0}\mu^+\mu^−$ 10.1103/PhysRevLett.111.191801 [2] Aaij, Roel and others Angular analysis of the $B^0\to K^{∗0}\mu^+\mu^−$ decay arXiv/1512.04442

Speaker: Simon Wehle (DESY Hamburg)

wehle.pdf

19:20 N-jettiness at NNLO accuracy in electron-positron annihilation

Vetoing undesired jets is essential in many analyses aiming at searches for new particles. A new jet function, called N-jettiness has been introduced with the purpose of using an inclusive event shape variable for vetoing jets. The logarithms from the phase space restriction, are simple enough to allow their systematic summation to all orders, which allows for providing high precision predictions that combine the fixed-order and resummed results. In this talk we present predictions for two- and three-jettiness in electron-positron annihilation at the next-to-next-to-leading order accuracy. We use the CoLoRFulNNLO subtraction scheme, which is implemented in a computer program that can be used for computing arbitrary jet cross sections at NNLO provided the necessary matrix elements are supplemented.

Speaker: Zoltán Tulpiánt (University of Debrecen)

N-jettiness at NNLO accuracy in electron-positron annihilation.pdf

19:30 Searches for LFV H/Z → τ e / τ µ decays with the ATLAS detector at 8 TeV

Direct searches for lepton–flavour–violation (LFV) in decays of the Z and recently discovered Higgs boson with the ATLAS detector at the LHC are presented. Three LFV decays are considered: H → eτ, H → µτ, and Z → µτ. The searches are based on the data sample of proton–proton collisions collected by the ATLAS detector corresponding to an integrated luminosity of 20.3 fb−1 at a center–of–mass energy of √s = 8 TeV.

Speaker: Hartger Weits (NIKHEF (NL))

presentation.pdf

20:00 → 22:30 Conference Dinner

Friday, 15 April

08:20 → 09:00 Ultra-high multiplicity electroweak production at Future Colliders - Perturbation theory meltdown and Beyond

Speaker: Valentin V Khoze (Durham University)

Khoze_LHCSki.pdf

09:00 → 09:40 Towards the Next Standard Model: Experimental Challenges

Speaker: Christian Kiesling (Werner-Heisenberg-Institut)

LHCSki2016_CK.pdf

09:40 → 10:10 Coffee

10:10 → 10:50 Outlook

Speaker: Tilman Plehn (Heidelberg University)

tilman_obergurgl.pdf