Search for high-mass dilepton resonances with the ATLAS detector
|
|
- Kathryn Briggs
- 6 years ago
- Views:
Transcription
1 1 Search for high-mass dilepton resonances with the ATLAS detector, Michigan State University Experimental Particle Physics Seminar University of Pennsylvania,
2 2 Overview 1. Why are we looking for high-mass dilepton resonances? 2. 1fb-1 analysis (Phys. Rev. Lett. 107, (2011)) - event selection - backgrounds - high energy electrons and muons - signal search and limit setting 3. 5 fb-1 analysis (in preparation) - updates
3 Why are we looking for Physics beyond the SM? The Standard Model of Particle Physics is a very successful theory, but cannot be the end of the story... For example, it doesn't - have a dark matter candidate - explain, why gravity is so weak compared to the other fundamental forces Also: Before we find the Higgs, we cannot be sure of how electroweak symmetry is broken 3
4 Search for dilepton resonances (ee/μμ) q/g q/g 4 l +? l -
5 5 Search for dilepton resonances Dilepton resonances have been the window to a better understanding of elementary particles and forces before... Here be dragons
6 6 Search for dilepton resonances Dilepton resonances could be a signature of - new heavy gauge boson in the E6 model (Grand Unified Theory model) ----> spin-1 - excited Kaluza-Klein mode of the Randall Sundrum graviton ----> spin-2...and many others (resonance search is fairly model independent) Benchmark model: Sequential Standard Model Z' (same couplings as Z boson), not theoretically motivated
7 7 Additional symmetries Dilepton resonances could be a signature of - new heavy gauge boson in the E6 model (Grand Unified Theory model) (Phys. Rev. D 34 (1986), arxiv: v3) GUT theories: Unification of electroweak and strong forces at high energies ----> 1 overall symmetry, which breaks down at lower energies 2 additional U(1) groups lead to Z' Several motivated choices of θe6
8 8 Randall Sundrum graviton Dilepton resonances could be a signature of - excited Kaluza-Klein mode of the Randall Sundrum graviton (arxiv:hep-ph/ v1) 1 finite warped extra dimension, 2 branes Standard brane 2 parameters: - m1 (first excitation) - k (curvature) Planck brane G(x) 1 extra dimension 0.1 Only gravitons propagate to extra brane ----> wave functions are suppressed away from extra brane ----> gravity is weak! Finite extra dimension ----> excitation like in harmonic oscillator possible ----> Kaluza-Klein tower of massive graviton states
9 9-1 1 fb analysis
10 10 Event Selection electrons - ATLAS data quality (stable beam, functioning subdetectors etc.) - pick two standard electrons, central (η < 2.47), ET > 25 GeV - require track and EM shower shape cuts ( Medium ) - require hit in innermost layer of detector - leading electron should be isolated (calorimeter based) ---> energy in a cone of 0.2 around the electron < 7 GeV - form invariant mass, require mass > 70 GeV Main background: Z/γ* Acceptance (Z', 1.5 TeV): 67%
11 11 Event Selection muons - ATLAS data quality (stable beam, functioning subdetectors etc.) - pick two standard combined muons, pt > 25 GeV - require 3 hits in 3 muon spectrometer layers, no overlap barrel-endcap, veto misaligned chambers - distance from primary vertex needs to be small - require tracks to be isolated - muons must have opposite charge - form invariant mass, require mass > 70 GeV Main background: Z/γ* Acceptance (Z', 1.5 TeV): 42%
12 12 Backgrounds Backgrounds with two prompt electrons/muons: - Drell Yan - WW,WZ,ZZ - ttbar (dileptonic decay) Backgrounds with QCD jets, which can fake prompt leptons - W+jets - QCD multijet production ----> what is the fake rate at high energies? Drell Yan is dominant background by far, all background except for QCD multijet taken from simulated samples
13 QCD multijet background electrons 13 Jets can fake electrons. How large is the fake rate? 1. Baseline Method Reverse Identification - dijet shape from reverted electron identification cuts - extrapolation to high invariant masses by fitting with empirical function - normalization by 2-component template fit 2. Cross-check and systematic uncertainties Isolation fit method Fake rate estimate - use calorimeter isolation distributions - measure probability for jet-like - fit signal/background templates from data for 1st and 2nd electron - system of equations to avoid double counting objects to pass Z' selection (η, ET) - apply fake rate on normalization sample (Z' selection on leading, jet selection on second electron)
14 14 QCD multijet background muons QCD multijet background much smaller for muons 1. Shape: Anti-track-isolated data ( ) 2. Normalization: Ratio of isolated ( ) /anti-isolated ( ) dimuon events in QCD (heavy flavor) simulated samples QCD from simulation
15 High pt leptons 15 Looking for resonances at high invariant masses ---> need to understand properties of highly energetic objects in ATLAS Very small control sample, handles: calibration runs, cosmics, Tag-and-Probe around Z pole ---> extrapolation, simulation
16 16 High pt leptons resolution Electrons (Resolution % at 1 TeV): - energy measurement from electromagnetic calorimeter - resolution at high energies dominated by constant term - improvement at high energies of linearity and resolution shown in calibration runs Muons (Resolution > 15% at 1 TeV): - pt measurement from hits in inner detector and muon spectrometer - require stringent cuts on number of hits, veto misaligned areas - measured (as a function of pt) using cosmics, magnet off runs, overlap regions, inner detector vs. muon spectrometer comparisons, Z peak
17 17 Efficiencies and scale factors Determine trigger, reconstruction and identification efficiencies in data with Tag-and-Probe l+ - allows to get relatively unbiased control sample by applying strict cuts on Tag and test efficiency on Probe (p.ex. Z ---> l+l-) l- Z - electrons: need to subtract QCD jet background - leptons from W/Z decay: no estimate above ~200 GeV - extrapolation by observing of trends, simulation Electrons: No decrease of selection efficiency expected at high energies (careful with isolation cut) Muons: highly energetic muons occasionally radiate so much bremsstrahlung, that their tracks might be too distorted for reconstruction
18 18 Invariant mass distributions Electrons Muons The MC and QCD estimate are normalized to data in the mass range GeV (Normalization factor: 99% for both electron and muon channel.)
19 19 Systematic Uncertainties Uncertainties on yield at invariant mass of 1.5 TeV: - only mass-dependent uncertainties are considered - no theoretical uncertainties on signal (by convention) (except for 5% Z boson cross-section uncertainty, which replaces the luminosity uncertainty) - uncertainties below 2% negligible (Pileup, energy calibration, momentum/energy resolution, electron trigger, reconstruction, identification efficiency, QCD multijet estimate)
20 20 Signal templates Two templates for every tested signal mass: Z' (spin-1) - limits will be set on Z' (SSM) and motivated Z' (E6) - use shape of Sequential Standard Model Z' - neglect interference with DY - reweight flat sample (with Breit-Wigner, Parton Luminosity) G* (spin-2): 1 - limits will be set for different couplings ( ) - use shape with largest width (0.1) - fully simulated (in 5fb-1 analysis: flat sample) 0.1 Phys.Rev. D63 (2001)
21 21 Statistical Method Likelihoods - compare invariant mass distribution in data with SM background and signal templates (for invariant masses above 130 GeV) - binned Poisson likelihood (invariant mass bins k): - Systematic uncertainties are considered through nuisance parameters (for which we assume Gaussian probability functions) - Reduced likelihood: Integral over all nuisance parameters - Convert Nsig to cross-section
22 Search for a signal 22 - use 2D maximum likelihood fit to find most probable M Z' and σz' - get p-value by comparing to background-only pseudo-experiments ---> what is the percentage of pseudo experiments, which show an excess at least as significant as the one seen in data - electrons: p = 54%, muons: p = 24% (evidence: 0.1%, discovery %) ---> No significant excess found ---> Setting limits
23 Statistical Method Setting limits 23 - Bayes theorem: - no prior knowledge on cross-section: - 95% confidence level (C.L.) limits can be set by finding upper edge of integral, such that: ----> with 95% C.L. we say, that σsigb is below (σsigb)95
24 24 Limits Spin 1 - Sequential Standard Model Z' as baseline model (same couplings as the Z boson) - different E6 models Limits on SSM Z' [TeV]: ee mumu combined Observed Expected Combined limits on E6 models [TeV]: Z' (ψ) Z' (N) Z' (η) Z' (I) Z' (S) Z' (χ) Previous limits on SSM Z' [TeV]: Tevatron (1.071), ATLAS (1.042), CMS (1.140) LEP (indirect, 1.79) -1 CMS 1 fb [TeV]: 1.94
25 25 Limits Spin 2 - Randall-Sundrum Graviton (different couplings) Limits on RS graviton (k/mpl = 0.1): ee mumu combined Observed Expected Combined limits for additional couplings: Coupling Previous limits on Gravitons (k/mpl = 0.1) [TeV]: CMS, CDF, D0 (all below 1.08) Combination with diphoton channel (2.2fb -1): 1.95 TeV (see next slide)
26 Limits G* - Combination with diphoton channel26 - diphoton branching fraction ~2 times dielectron/dimuon - limits on Gravitons (k/mpl = 0.1) [TeV]: 1.85 (diphoton), 1.95 (diphoton+dilepton)
27 Technicolor search (ATLAS-CONF ) 27 Alternative mechanism of electroweak symmetry breaking (no scalar Higgs) Low Scale Technicolor model (Lane, Eichten): techni-isospin good symmetry QCD-like technihadron spectrum: near-degenerate ρt, ωt narrow spin-1 resonance, same acceptance as Z' ---> same cross-section limits as for the Z' analysis Low Scale technicolor interpretation of CDF Wjj excess (Phys. Rev. Lett. 106 (2011) )
28 Non-resonant search: Contact Interactions arxiv: v2 28 (same event selection as for Z' search) - looking for broad excess at high dilepton masses - models: quark/lepton compositeness, exchange particles at masses inaccessible to LHC energies cross-section: XS ~ XS(DY) η FI/Λ + FC/Λ ---> prior chosen flat in 1/Λ2 and alternatively 1/Λ4 p-values in signal search > 5% ---> set limits η= +/- 1 (pos./neg. interference) Λ: scale
29 fb analysis (full 2011 dataset)
30 30 Status of the analysis Two parts: ---> conference result showing limits on Z', G* for Moriond Electroweak (approved by collaboration last week, awaiting final sign off) ---> more extensive paper in a couple of weeks Improvements: ---> better background estimates ---> 2 station muons (already in conference note) ---> limits on more models (will be in paper)
31 31 2-station muons Low acceptance in muon channel due to strict cuts on the hits in the muon spectrometer (inner, middle, outer layer) ----> decent momentum resolution ----> but three layers not available for every region of the detector Inclusion of 2-station muons - 1 leg 3 stations, 1 leg 2 stations - combined muons (inner detector and spectrometer) - require 5 hits in each of the inner and outer layer - veto regions with misalignments - significance cut (ID-MS): 3σ (instead of 5 like for 3-station muons) ---> acceptance increase by ~4% (absolute) ---> resolution ~25% (dominated by inner detector)
32 32 Models - setting limits on more models: Z', G*, arxiv: v2 Z*, Technicolor (MWTC, LSTC), Torsion, Kaluza-Klein Z'/γ* - model independent limits: Minimal Z' models - template production from DY for many models, using matrix elements or generator level distributions - limits on couplings instead of cross-sections, including interference effects (for Kaluza-Klein, Minimal models)
33 33 5 fb-1 analysis: Minimal Z' models - class of models with same coupling structure, parametrized by y' and cos(θ) (arxiv: v2) - known models in this parametrization: - make templates by reweighting DY illustration with matrix element ---> includes interference and width - set limit on coupling y'
34 34 Conclusion - search for high-mass dielectron and dimuon resonances with the ATLAS detector - no significant excess found in 1 fb-1 - lower mass limits set on Z' models, RS graviton, technimesons in Low Scale Technicolor - 5 fb-1 analysis with improvements is underway
35 35 BACKUP
36 Event yield tables 36
37 Tight muon selection 37
38 Tight-loose muon selection 38
39 Event Display (mee = 993 GeV ) 39
40 Event Display (mμμ = 959 GeV ) 40
41 Branching fractions graviton decay 41 arxiv:hep-ph/ v1
42 Minimal Z' Models (arxiv: v2) 42 Class of models with following couplings: ul,dl ur dr νl,el νr er 1/6 gy+1/3 gbl 2/3 gy+1/3gbl -1/3 gy+1/3 gbl -1/2 gy- gbl -gbl -gy-gbl gy = γ' cos θ, gbl = γ' sin θ ----> two parameters (γ', θ) Known models covered by this parametrization:
Searches for exotic particles in the dilepton and lepton plus missing transverse energy final states with ATLAS
Searches for exotic particles in the dilepton and lepton plus missing transverse energy final states with ATLAS, Vanja Morisbak, Farid Ould-Saada Spåtind conference January 4th 2012 Motivation In spite
More informationNew physics searches with dileptons and diphotons at ATLAS
New physics searches with dileptons and diphotons at ATLAS Martina Hurwitz Lawrence Berkeley National Laboratory On behalf of the ATLAS collaboration SEARCH conference University of Maryland March, 2012
More informationExotics Searches for New Physics with the ATLAS Detector
Exotics Searches for New Physics with the ATLAS Detector Jalal Abdallah IFAE Barcelona on behalf of ATLAS Collaboration 19th Particles & Nuclei International Conference 24-29 July 2011 Outline New results
More informationW. Fedorko for the ATLAS collaboration
W. Fedorko for the ATLAS collaboration The Standard Model very well tested BUT: No way to incorporate gravity No viable dark matter candidate Hierarchy problem W. Fedorko High Mass resonances at ATLAS
More informationExotics Searches in Photon and Lepton Final States with the ATLAS Detector
Exotics Searches in Photon and Lepton Final States with the ATLAS Detector Tetiana Berger-Hryn ova (LAPP, Annecy le Vieux) on behalf of the ATLAS collaboration EPS, Grenoble, France 21 July 2011 1 Introduction
More informationSEARCH FOR EXTRA DIMENSIONS WITH ATLAS AND CMS DETECTORS AT THE LHC
SEARCH FOR EXTRA DIMENSIONS WITH ATLAS AND CMS DETECTORS AT THE LHC S. SHMATOV for ATLAS and CMS Collaborations Joint Institute for Nuclear Research, Dubna, Russia E-mail: shmatov@cern.ch A brief review
More informationSearching for New High Mass Phenomena Decaying to Muon Pairs using Proton-Proton Collisions at s = 13 TeV with the ATLAS Detector at the LHC
Proceedings of the Fifth Annual LHCP ATL-PHYS-PROC-07-089 August 9, 07 Searching for New High Mass Phenomena Decaying to Muon Pairs using Proton-Proton Collisions at s = TeV with the Detector at the LHC
More informationPhysics at Hadron Colliders
Physics at Hadron Colliders Part 2 Standard Model Physics Test of Quantum Chromodynamics - Jet production - W/Z production - Production of Top quarks Precision measurements -W mass - Top-quark mass QCD
More informationCMS Searches for New Physics
CMS Searches for New Physics Christian Autermann, for the CMS collaboration I. Phys. Inst. RWTH Aachen University, Germany QCD14 2 Overview Searches for New Physics at CMS Inclusive search for Supersymmetry
More informationSearch for Extra Dimensions with the ATLAS and CMS Detectors at the LHC
Available on CMS information server CMS CR 2006/086 October 31, 2006 Search for Extra Dimensions with the ATLAS and CMS Detectors at the LHC Sergei Shmatov Joint Institute for Nuclear Research, Dubna,
More informationSearch for a heavy gauge boson W e
Search for a heavy gauge boson W e Cornell University LEPP Journal Club Seminar April 1, 2011 The LHC Machine 2 The beginning of the LHC era First collisions at 7 TeV confirmed on March 30, 2010 There
More informationHiggs-related SM Measurements at ATLAS
Higgs-related SM Measurements at ATLAS Junjie Zhu University of Michigan 2 nd MCTP Spring Symposium on Higgs Boson Physics Outline Introduction Isolated γγ cross section (37 pb -1, Phys. Rev. D 85, 012003
More informationPhysics with Tau Lepton Final States in ATLAS. Felix Friedrich on behalf of the ATLAS Collaboration
Physics with Tau Lepton Final States in ATLAS on behalf of the ATLAS Collaboration HEP 2012, Valparaiso (Chile), 06.01.2012 The Tau Lepton m τ = 1.8 GeV, heaviest lepton cτ = 87 μm, short lifetime hadronic
More informationSearch for high mass diphoton resonances at CMS
Search for high mass diphoton resonances at CMS 51st Rencontres de Moriond Electroweak session Thursday 17th 2016, La Thuile (Italy) Pasquale Musella (ETH Zurich) on behalf of the CMS collaboration Motivation
More informationOn behalf of the ATLAS and CMS Collaborations
On behalf of the ATLAS and CMS Collaborations Reza Goldouzian Université libre de Bruxelles 1 Ø There are several models of physics beyond the standard model require new particles that couple to quarks
More informationATLAS-CONF October 15, 2010
ATLAS-CONF-2010-096 October 15, 2010 Data-driven background estimation for the H τ + τ τ h search at 7 TeV with the ATLAS detector Ian Howley 7 December 2010 1 Motivation One of the primary LHC physics
More informationPoS(EPS-HEP2011)250. Search for Higgs to WW (lνlν, lνqq) with the ATLAS Detector. Jonas Strandberg
with the ATLAS Detector Royal Institute of Technology, KTH, Stockholm, Sweden E-mail: jostran@kth.se Higgs boson searches in the H WW ( ) lνlν (l = e, µ) and the H WW ( ) lνqq decay modes, using. fb of
More informationPoS(Kruger 2010)034. CMS searches for new physics. Mara Senghi Soares On behalf of the CMS Collaboration.
On behalf of the CMS Collaboration E-mail: mara.senghi@ciemat.es We discuss the first searches for new physics being carried out with the CMS detector, at the early stage of data taking. Prospects for
More informationRecent Results on New Phenomena and Higgs Searches at DZERO
Recent Results on New Phenomena and Higgs Searches at DZERO Neeti Parashar Louisiana Tech University Ruston, Louisiana U.S.A. 1 Outline Motivation for DØ Run II Detector at Fermilab The Fermilab Tevatron
More informationSearches for new physics at ATLAS
1 Searches for new physics at ATLAS Gökhan Ünel U.C. Irvine On behalf of the ATLAS collaboration ICPP 2011 Istanbul Outline 2 LHC has been giving us data at ever increasing pace. Lint =1 fb reached as
More informationEarly physics with Atlas at LHC
Early physics with Atlas at LHC Bellisario Esposito (INFN-Frascati) On behalf of the Atlas Collaboration Outline Atlas Experiment Physics goals Next LHC run conditions Physics processes observable with
More informationPerformance of muon and tau identification at ATLAS
ATL-PHYS-PROC-22-3 22/2/22 Performance of muon and tau identification at ATLAS On behalf of the ATLAS Collaboration University of Oregon E-mail: mansoora.shamim@cern.ch Charged leptons play an important
More informationReview of ATLAS experimental results (II)
Review of ATLAS experimental results (II) Rachid Mazini Academia Sinica Taiwan CTEQ 2012 summer school Lima, Peru 30 July -8 August Rachid Mazini, Academia Sinica 1 Outline part II Higgs searches H, H
More informationSearch for the SM Higgs boson in the decay channel H ZZ ( * ) 4l in ATLAS
Search for the SM Higgs boson in the decay channel H ZZ ( * ) 4l in ATLAS Luis R Flores Castillo University of Wisconsin-Madison On behalf of the ATLAS Collaboration Higgs Hunting 2012 July 19, 2012 Orsay
More informationDark matter searches and prospects at the ATLAS experiment
Dark matter searches and prospects at the ATLAS experiment Wendy Taylor (York University) for the ATLAS Collaboration TeVPA 2017 Columbus, Ohio, USA August 7-11, 2017 Dark Matter at ATLAS Use 13 TeV proton-proton
More informationPoS(CORFU2016)060. First Results on Higgs to WW at s=13 TeV with CMS detector
First Results on Higgs to WW at s=13 ev with CMS detector Università di Siena and INFN Firenze E-mail: russo@fi.infn.it he first measurement of the Higgs boson cross section at 13 ev in H WW 2l2ν decay
More informationSearch for the Higgs Boson In HWW and HZZ final states with CMS detector. Dmytro Kovalskyi (UCSB)
Search for the Higgs Boson In HWW and HZZ final states with CMS detector Dmytro Kovalskyi (UCSB) Introduction WW and ZZ finals states dominate Higgs searches at Higgs Mass WW 2L2ν has best sensitivity
More informationarxiv: v1 [hep-ex] 8 Nov 2010
Searches for Physics Beyond the Standard Model at CMS Sung-Won Lee, on behalf of the CMS Collaboration Texas Tech University, Lubbock, TX 799, USA Recent results on searches for physics beyond the Standard
More informationHiggs Boson Searches at ATLAS
Higgs Boson Searches at ATLAS Jianming Qian University of Michigan October 5, 2011 Maryland/John Hopkins Joint Seminar, October 5, 2011 Jianming Qian (University of Michigan) 1 Standard Model Standard
More informationIdentification of the Higgs boson produced in association with top quark pairs in proton-proton
Identification of the Higgs boson produced in association with top quark pairs in proton-proton collision: an analysis of the final state containing three leptons with the ATLAS detector Valentina Vecchio,
More informationTop Physics in Hadron Collisions
Top Physics in Hadron Collisions Dirk Dammann DESY 2010-02-04 1 / 44 Outline 1 2 3 4 2 / 44 Outline Motivation Top Production Top Decay Top Physics 1 Motivation Top Production Top Decay Top Physics 2 3
More informationHiggs Searches and Properties Measurement with ATLAS. Haijun Yang (on behalf of the ATLAS) Shanghai Jiao Tong University
Higgs Searches and Properties Measurement with ATLAS Haijun Yang (on behalf of the ATLAS) Shanghai Jiao Tong University LHEP, Hainan, China, January 11-14, 2013 Outline Introduction of SM Higgs Searches
More informationCMS Physics Analysis Summary
Available on the CERN CDS information server CMS PAS EXO-11-009 CMS Physics Analysis Summary Contact: cms-pag-conveners-exotica@cern.ch 01/05/06 Search for Contact Interactions in µ + µ Events in pp Collisions
More informationHiggs couplings and mass measurements with ATLAS. Krisztian Peters CERN On behalf of the ATLAS Collaboration
Higgs couplings and mass measurements with ATLAS CERN On behalf of the ATLAS Collaboration July observation: qualitative picture A single state observed around ~125 GeV Qualitatively all observations consistent
More informationSearches for Physics Beyond the Standard Model with the ATLAS Detector
Searches for Physics Beyond the Standard Model with the ATLAS Detector On behalf of the ATLAS Collaboration XXVI Rencontres de Physique de la Vallée d'aoste La Thuile, Feb 26 th March 3 rd, 2012 Why search
More informationSearch for the Standard Model Higgs Boson in H WW lν lν with the ATLAS experiment
Search for the Standard Model Higgs Boson in H WW lν lν with the ATLAS experiment MCTP Symposium 2012, University of Michigan, Ann Arbor, US Outline SM Higgs Boson production and decay Analysis based on
More informationSearches for new heavy resonances and extra dimensions at CMS
Searches for new heavy resonances and extra dimensions at CMS IHEP of Beijing, On behalf of the CMS collaboration E-mail: francesco.romeo@cern.ch Final states with a pair of particles are sensitive to
More informationStandard Model physics with taus in ATLAS
Standard Model physics with taus in ATLAS IFJ PAN, Cracow, Poland Why we are interested in taus? Tau leptons play an important role in the physics program of the ATLAS experiment as they are tools in many
More informationNON-SUSY SEARCHES FOR PHYSICS BEYOND THE STANDARD MODEL AT THE TEVATRON
Vol. 38 (7) ACTA PHYSICA POLONICA B No NON-SUSY SEARCHES FOR PHYSICS BEYOND THE STANDARD MODEL AT THE TEVATRON Sung-Won Lee on behalf of the CDF and DØ Collaborations Texas Tech University 5 Broadway,
More informationSearch for high mass resonances in the diphoton and Zγ channels at LHC
Search for high mass resonances in the diphoton and Zγ channels at LHC Matteo Bauce, Riccardo Paramatti Univ. Sapienza & INFN Roma Diphoton and flavor anomalies 23 rd May 2016 LHC Run2 started one year
More informationFeasibility of a cross-section measurement for J/ψ->ee with the ATLAS detector
Feasibility of a cross-section measurement for J/ψ->ee with the ATLAS detector ATLAS Geneva physics meeting Andrée Robichaud-Véronneau Outline Motivation Theoretical background for J/ψ hadroproduction
More informationTop Quark Studies with CMS
Top Quark Studies with CMS Frank-Peter Schilling (KIT) on behalf of the CMS collaboration The TOP Top Physics at the LHC Precise SM measurements o Heaviest known elementary particle (large Yukawa coupling)
More informationMeasurement of the Z ττ cross-section in the semileptonic channel in pp collisions at s = 7 TeV with the ATLAS detector
Measurement of the Z ττ cross-section in the semileptonic channel in pp collisions at s = 7 TeV with the ATLAS detector Sofia Consonni Università di Milano & INFN XCVII Congresso Nazionale della Società
More informationDilepton Forward-Backward Asymmetry and electroweak mixing angle at ATLAS and CMS
Dilepton Forward-Backward Asymmetry and electroweak mixing angle at ATLAS and CMS University of Rochester E-mail: jyhan@fnal.gov We present measurements of the forward-backward asymmetry in Drell-Yan dilepton
More informationIn Pursuit of the Next Discovery: A New Neutral Resonance. Chris Hays, Oxford University
In Pursuit of the Next Discovery: A New Neutral Resonance Chris Hays, Oxford University Royal Holloway, University of London May 13, 2009 A Brief History of Neutral Resonances J/ψ discovery 1970: Fourth
More informationThe search for standard model Higgs boson in ZH l + l b b channel at DØ
The search for standard model Higgs boson in ZH l + l b b channel at DØ University of Science and Technology of China E-mail: pengj@fnal.gov on behalf of the DØ collaboration We present a search for the
More informationElectroweak results. Luca Lista. INFN - Napoli. LHC Physics
Electroweak results Luca Lista INFN - Napoli EWK processes at LHC p p W and Z production in pp collisions proceeds mainly form the scattering of a valence quark with a sea anti-quark The involved parton
More informationInclusive top pair production at Tevatron and LHC in electron/muon final states
Inclusive top pair production at Tevatron and LHC in electron/muon final states Andreas Jung for the ATLAS, CDF, CMS and D Collaboration Fermilab, DAB5 - MS 357, P.O. Box 5, Batavia, IL, 651, USA DOI:
More informationSearching for the Higgs at the Tevatron
Searching for the Higgs at the Tevatron 5 th May 2009 Particle Physics Seminar, Oxford Outline Introduction The challenges and analysis strategies Low mass SM Higgs searches High mass SM Higgs searches
More informationMono-X, Associate Production, and Dijet searches at the LHC
Mono-X, Associate Production, and Dijet searches at the LHC Emily (Millie) McDonald, The University of Melbourne CAASTRO-CoEPP Joint Workshop Melbourne, Australia Jan. 30 - Feb. 1 2017 M. McDonald, University
More informationRecent ATLAS measurements in Higgs to diboson channels
Recent ATLAS measurements in Higgs to diboson channels Yusheng Wu University of Michigan Institute of Physics, Academia Sinica On behalf of the ATLAS collaboration August 31 st - Higgs Hunting 2016 Introduction
More informationA consideration of the search for graviton resonances in the diphoton decay mode at the ATLAS detector
A consideration of the search for graviton resonances in the diphoton decay mode at the ATLAS detector Marco Almeida (Vassar College) Columbia University, Nevis Labs 2006 REU Advisor: Kamal Benslama, John
More informationElectroweak Physics at the Tevatron
Electroweak Physics at the Tevatron Adam Lyon / Fermilab for the DØ and CDF collaborations 15 th Topical Conference on Hadron Collider Physics June 2004 Outline Importance Methodology Single Boson Measurements
More informationSearches for New Phenomena with Lepton Final States at the Tevatron
Searches for New Phenomena with Lepton Final States at the Tevatron including charginos, neutralinos,, excited leptons and unexpected signatures Todd Adams Florida State University for the CDF and DØ Collaborations
More informationSearch for Pair Production of Stop Quarks Mimicking Top Event Signatures
CDF/PUB/TOP/PUBLIC/9343 Search for Pair Production of Stop Quarks Mimicking Top Event Signatures The CDF Collaboration URL http://www-cdf.fnal.gov May 29, 2008 Abstract We present the search for the pair-produced
More informationLa ricerca dell Higgs Standard Model a CDF
La ricerca dell Higgs Standard Model a CDF Melisa Rossi INFN-TS Giornata di seminari INFN Trieste - 7 Luglio 2009 FNAL: Fermi National Accelerator Lab Tevatron currently provides the highest energy proton-antiproton
More informationRecent Results from the Tevatron
Recent Results from the Tevatron Simona Rolli Tufts University (on behalf of the CDF and D0 Collaborations) PPC 2010: IV INTERNATIONAL WORKSHOP ON THE INTERCONNECTION BETWEEN PARTICLE PHYSICS AND COSMOLOGY
More informationPDF Studies at LHCb! Simone Bifani. On behalf of the LHCb collaboration. University of Birmingham (UK)
PDF Studies at LHCb! Simone Bifani University of Birmingham (UK) On behalf of the LHCb collaboration MENU 213 Rome 3th September - 4th October 213 Outline Introduction Analyses» Z/γ* ll, l =, e, τ#» W
More informationSearches for New Physics in Photonic Final States at the LHC with CMS
Searches for New Physics in Photonic Final States at the LHC with CMS APS April Meeting Denver CO, May 03, 2009 Andy Yen California Inst. of Technology CMS Collaboration 1 The CMS Detector CMS is general
More informationHiggs Boson at the CMS experiment
16 th Lomonosov Conference on Elementary Particle Physics 22 28 August 2013, Moscow (Russia) Higgs Boson at the CMS experiment Somnath Choudhury (for the CMS collaboration) 5.1 fb -1 @ 7 TeV + 5.3 fb -1
More informationSearches for Strong Dynamics at the TEVATRON
Searches for Strong Dynamics at the TEVATRON Hereafter I Present Preliminary Results on Behalf of the CDF and D0 Collaborations OUTLINE I. Introduction II. Search for Excited Electrons III. Search for
More informationHiggs search in WW * and ZZ *
Higgs search in WW * and ZZ * Emanuele Di Marco on behalf of CMS collaboration La Sapienza Università di Roma & INFN Roma1 July, 29 2011 1 Higgs production at LHC gluon fusion (gg H) gg H is the dominant
More informationRecent QCD results from ATLAS
Recent QCD results from ATLAS PASCOS 2013 Vojtech Pleskot Charles University in Prague 21.11.2013 Introduction / Outline Soft QCD: Underlying event in jet events @7TeV (2010 data) Hard double parton interactions
More informationSeminario finale di dottorato
Seminario finale di dottorato Search for new physics in dielectron and diphoton final states at CMS 17/05/2017 Giuseppe Fasanella La Sapienza University of Rome & INFN Roma 1 Co-supervision with ULB Université
More informationHighlights of top quark measurements in hadronic final states at ATLAS
Highlights of top quark measurements in hadronic final states at ATLAS Serena Palazzo 1,2,, on behalf of the ATLAS Collaboration 1 Università della Calabria 2 INFN Cosenza Abstract. Measurements of inclusive
More informationSearches for Exotic Physics with the ATLAS Detector
Searches for Exotic Physics with the ATLAS Detector Emily Thompson University of Massachusetts, Amherst on behalf of the ATLAS Collaboration Rencontres de Moriond 2011 QCD and High Energy Interactions
More informationEW Physics at LHC. phi= mu_4: pt=7.9 GeV, eta=-1.13, phi=0.94. Toni Baroncelli:
EW Physics at LHC Event display of a 2e2mu candidate. EventNumber: 12611816 RunNumber: 205113 m_4l=123.9 GeV. m_12=87.9 GeV, m_34=19.6 GeV. e_1: pt=18.7 GeV, eta=-2.45, phi=1.68,. 15/09/17 e_2: pt=75.96
More informationFuture prospects for the measurement of direct photons at the LHC
Future prospects for the measurement of direct photons at the LHC David Joffe on behalf of the and CMS Collaborations Southern Methodist University Department of Physics, 75275 Dallas, Texas, USA DOI:
More informationTevatron Non-SUSY BSM: Searches for Physics Beyond the SM and MSSM. David Stuart University of California, Santa Barbara. DIS 2007, Munich April 2007
Tevatron Non-SUSY BSM: Searches for Physics Beyond the SM and MSSM David Stuart University of California, Santa Barbara DIS 2007, Munich April 2007 Outline There are two categories of searches: 1. Model
More informationQCD Multijet Background and Systematic Uncertainties in Top Physics
QCD Multijet Background and Systematic Uncertainties in Top Physics Jin Wang On behalf of ATLAS, CMS, CDF and D0 Collaborations IHEP, China 2013-09-15, Top2013 1 Outline Introduction of QCD Multijet Background
More informationSearch for W' tb in the hadronic final state at ATLAS
Search for W' tb in the hadronic final state at ATLAS Ho Ling Li The University of Chicago January 5, 2015 1 Introduction What is W'? A charged, heavy, Standard-Model-like W gauge boson Analysis channels
More informationBSM physics at the LHC. Akimasa Ishikawa (Kobe University)
BSM physics at the LHC Akimasa Ishikawa (Kobe University) 7 Jan. 2011 If SM Higgs exists Why BSM? To solve the hierarchy and naturalness problems O(1 TeV) Quadratic divergence of Higgs mass If SM Higgs
More informationMeasurement of Z+ Jets Cross-Section at ATLAS
Measurement of Z+ Jets Cross-Section at The collaboration Abstract The production of a W or Z boson in conjunction with jets is an interesting process in its own right as well as a signal channel (and
More informationHiggs Searches at CMS
Higgs Searches at CMS Ashok Kumar Department of Physics and Astrophysics University of Delhi 110007 Delhi, India 1 Introduction A search for the Higgs boson in the Standard Model (SM) and the Beyond Standard
More informationPhysics at Tevatron. Koji Sato KEK Theory Meeting 2005 Particle Physics Phenomenology March 3, Contents
Physics at Tevatron Contents Koji Sato KEK Theory Meeting 5 Particle Physics Phenomenology March 3, 5 mass measurement Top physics cross section Top mass measurement SM Higgs search Tevatron Run II Started
More information2 ATLAS operations and data taking
The ATLAS experiment: status report and recent results Ludovico Pontecorvo INFN - Roma and CERN on behalf of the ATLAS Collaboration 1 Introduction The ATLAS experiment was designed to explore a broad
More informationSearch for long-lived particles at CMS
Search for long-lived particles at CMS Jie Chen Florida State University for the CMS Collaboration 03/19/12 Jie Chen @ SEARCH12 1 Outline Brief introduction to long-lived particle Neutral long-lived particles
More informationSearching for the Randall-Sundrum Graviton decay to dielectron pairs. Meghan Frate Bucknell University
Searching for the Randall-Sundrum Graviton decay to dielectron pairs Meghan Frate Bucknell University 1 The Project Look for evidence of the Randall- Sundrum Graviton using ee events at the LHC using the
More informationSearches for Techniparticles at DØ
Searches for Techniparticles at DØ Technicolor Physics Lorenzo Feligioni Boston University Electroweak Symmetry Breaking Previous Searches Current Searches at DØ: b-tagging W π T e ν b b/c Event selection
More informationCMS. S.Paktinat. School of Particles and Accelerators Institute for Studies in Theoretical Physics and Mathematics (IPM) May 23, 2013
IPM @ CMS S.Paktinat School of Particles and Accelerators Institute for Studies in Theoretical Physics and Mathematics (IPM) May 23, 2013 The CMS detector for LHC Each color shows a different layer This
More informationZZ 4l measurement with the first ATLAS data
ZZ 4l measurement with the first ATLAS data XXVIII PHYSICS IN COLLISION Perugia, Italy, 25-28 June 2008 For the ATLAS collaboration: Ilektra A. Christidi Aristotle University of Thessaloniki, Greece Overview
More informationQCD and Top physics studies in proton-proton collisions at 7 TeV centre-of-mass energy with the ATLAS detector
Journal of Physics: Conference Series QCD and Top physics studies in proton-proton collisions at 7 TeV centre-of-mass energy with the ATLAS detector To cite this article: Marcello Barisonzi 2012 J. Phys.:
More informationInclusive SUSY Searches at CMS with Emphasis on Detector Systematics
Inclusive SUSY Searches at with Emphasis on Detector Systematics R. Cavanaugh (on behalf of ) University of Florida SUSY06 Detector Background Calibrations Inclusive Search Strategies Detector Systematics
More informationSearch for Higgs and new Physics at CDF
Search for Higgs and new Physics at CDF Outline: Search for Standard Model Higgs Introduction Analysis methods for low mass Higgs Strategies for high mass Higgs Search for new Physics Signature based Electron
More information14th Lomonosov Conference on Elementary Particle Physics Moscow, 24 August 2009
M. Biglietti University of Rome Sapienza & INFN On behalf of the ATLAS Collaboration 1 14th Lomonosov Conference on Elementary Particle Physics Moscow, 24 August 2009 Theoretically favored candidates for
More informationStudy of Higgs boson leptonic decay modes
Study of Higgs boson leptonic decay modes Windows on the Universe ICSE, Vietnam 11-17.08.2013 Pawel Brückman de Renstrom on behalf of the ATLAS, CMS, CDF, D0 Collaborations ( Institute of Nuclear Physics
More informationExcited Electron Search in the e eeγ Channel in ATLAS at S = 7 TeV
Excited Electron Search in the e eeγ Channel in ATLAS at S = 7 TeV Juliana Cherston August 5, 11 Abstract The discovery of an excited electron would provide evidence for the theory of compositeness. In
More informationHiggs Boson in Lepton Decay Modes at the CMS Experiment
Higgs Boson in Lepton Decay Modes at the Experiment Somnath Choudhury 1 for the collaboration 1 DESY - Hamburg, Germany DOI: http://dx.doi.org/1.34/desy-proc-14-4/1 The results on the standard model Higgs
More informationSearches at Accelerators
Searches at Accelerators University of Liverpool Outline Why search for Extra Dimensions (ED)? Motivation & different models: ADD, RS, TeV - How are ED detectable at accelerators? Signatures Where are
More informationPhysics at the Tevatron. Lecture IV
Physics at the Tevatron Lecture IV Beate Heinemann University of California, Berkeley Lawrence Berkeley National Laboratory CERN, Academic Training Lectures, November 2007 1 Outline Lecture I: The Tevatron,
More informationMeasurement of Фs, ΔΓs and Lifetime in Bs J/ψ Φ at ATLAS and CMS
Measurement of Фs, ΔΓs and Lifetime in Bs J/ψ Φ at ATLAS and CMS Claudio Heller Excellence Cluster Universe LMU München For the ATLAS and CMS Collaborations Beauty 2013 14th International Conference on
More informationProduction of multiple electroweak bosons at CMS
on behalf of the CMS Collaboration Northeastern University, Boston (USA) E-mail: daniele.trocino@cern.ch We present studies of diboson production in pp collisions at 7 TeV and 8 TeV center-of-mass energy
More informationSearches at the LHC: Results from first data
Searches at the LHC: Results from first data 23 March, 2011 Satyaki Bhattacharya SINP, Kolkata Plan of talk CMS Higgs, SUSY, Exotica results from Moriond Higgs SUSY Exotica main emphasis In exotica part
More informationEXOTICA AT LHC. Philippe Miné LPNHE-Ecole Polytechnique, IN2P3-CNRS, France CMS collaboration.
EXOTICA AT LHC Philippe Miné LPNHE-Ecole Polytechnique, IN2P3-CNRS, France CMS collaboration pmine@poly.in2p3.fr Chia, Sardinia, Italy October 24-27 2001 1 EXOTICA AT LHC Beyond the Standard Model, Supersymmetry
More informationPoS(EPS-HEP 2013)215. WW, WZ, and ZZ production at CMS. Jordi DUARTE CAMPDERROS (on behalf of CMS collaboration)
(on behalf of CMS collaboration) Universidad de Cantabria/CSIC E-mail: jorge.duarte.campderros@cern.ch We present the WW, WZ and ZZ production cross sections measurements and constraints on anomalous triple-gauge
More informationBeyond the standard model searches at the Tevatron
Beyond the standard model searches at the Tevatron G. Sajot To cite this version: G. Sajot. Beyond the standard model searches at the Tevatron. 3th International Symposium on Particles, Strings and Cosmology
More informationSearch for the High-Mass Standard Model Higgs Boson with the ATLAS Detector
Search for the High-Mass Standard Model Higgs Boson with the ATLAS Detector Sylvie Brunet Indiana University on behalf of the ATLAS collaboration Sylvie Brunet, Tau Fake Rate Plans, 02/10/2008 SEARCH 2012
More informationA Measurement Of WZ/ZZ ll+jj Cross Section. Rahmi Unalan Michigan State University Thesis Defense
A Measurement Of WZ/ZZ ll+jj Cross Section Rahmi Unalan Michigan State University Thesis Defense 1 Overview Physics Motivation DØ Detector Standard Model Triple Gauge Coupling Object Definitions WZ/ZZ
More informationIntroduction. The LHC environment. What do we expect to do first? W/Z production (L 1-10 pb -1 ). W/Z + jets, multi-boson production. Top production.
Introduction. The LHC environment. What do we expect to do first? W/Z production (L 1-10 pb -1 ). W/Z + jets, multi-boson production. Top production. Early discoveries? Conclusions. 2 First collisions
More informationProspects for early discoveries in final states. LRSM and Leptoquarks
ν ν lq Prospects for early discoveries in final states with di-leptons, jets and no missing energy: LRSM and Leptoquarks University Of Pittsburgh On behalf of the ATLAS Collaboration The ATLAS detector
More information