Review of the prospects for physics measurements with ATLAS and CMS using early LHC dat

Tapprogge, S

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ATL-PHYS-SLIDE-2009-31113October2009LHC physicswith early dataStefan Tapprogge Institut für PhysikPage 1DESY Theory Workshop   “Collider Phenomenology” HamburgSep. 29th – Oct. 2nd 2009           Contentsl Motivationl LHC   &   ATLAS and CMSl “Rediscovery” of Standard ModelDESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 2à … and morel New physics beyond SMl SummaryLHC motivation / expectationDESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 3l as discussed during the workshop already …LHC    &DESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 4ATLAS and CMSExpectation for 2009/2010à all numbers shown have uncertaintiesl start-up end of 2009m 1 month commissioningMike Lamont (August 2009)DESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 5l physics run through 2010m 1 month commissioning / pilot runà 3 months at √s = 7 TeVm 1 month ‘step-up’à 5 months at √s = 8-10 TeVà 1 month heavy ionsMike Lamont (August 2009)Expectation for 2009/2010 (cont’d)l instantaneous luminosity of up to 1-2∗1032 cm-2 s-1à at most 2-3 inelastic events per crossing (on average)l integrated luminosity (delivered by LHC)à up to 200-300 pb-1J. StirlingDESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 6à possibly shared between two c.m.s. energiesm 7    TeV  and  8-10  TeV l impact of reduced c.m.s. energy on cross-sections compared to designà MX = 100 GeVm 0.3-0.5 resp. 0.6-0.7 (7 resp. 10 TeV)à MX =    1 TeV      m 0.1-0.2 resp. 0.3-0.5 (7 resp. 10 TeV) J. StirlingATLAS and CMSDESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 7The ATLAS Collaboration, G. Aad et al., The ATLAS Experiment at the CERN Large Hadron Collider, JINST 3 (2008) S08003.The CMS Collaboration, S. Chatrchyan et al., The CMS Experiment at the CERN Large Hadron Collider, JINST 3 (2008) S08004.Energy deposited by muonsECALPoints- datatotalCommissioning with cosmic muonsCMS preliminaryDESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 8HCALradiativeionisationExperiments are functioning DESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 9Start-up of LHC physicsl threefold approach (not fully sequentially)1. detector (and reconstruction) understanding with collision datam beyond extensive commissioning with cosmic muons2. “re-discovery” of Standard Model ?DESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 10m establish how pp collisions really look like at LHCm followed later on by precision measurements3. search for new physics beyond the SMm and (precision) measurements of its propertiesdetectorunderstandingSM@LHCReferencesØ ATLAS: Expected Performance of the ATLAS Experimento CERN-OPEN-2008-020 or  arXiv 0901.0512Ø ATLAS:  further public resultso https://atlas-physco.web.cern.ch/atlas-physco/ATLASPubNotes.htmlDESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 11o https://twiki.cern.ch/twiki/bin/view/Atlas/AtlasResultsØ CMS:     “Physics TDR“ Ø CERN-LHCC-2006-001 or J.Phys. G 34 (2007) 995-1579Ø CMS:     “Post Physics TDR“ ResultsØhttps://twiki.cern.ch/twiki/bin/view/CMS/PhysicsResultsl most (simulation)  studies done for √s = 14 TeV à recently studies ‘published’ for √s = 10 TeV as well“re-discovery”of Standard ModelDESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 12(and more…)The complexity of pp at LHCDESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 13l Pile-up included or not yet ?Schema of pp collisionl interesting part: the hard scatterà but it does not come aloneJ. Stirling11 DESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 14R. Field, Acta Phys. Pol. B39 (2008) Vol. 10, 2611The SM menu (sort of)l minimum bias propertiesl underlying eventl jet productionà cross-section, di-jet mass and angular distribution, shapesl direct photon productionJ. StirlingDESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 15l W/Z productionà incl. in association with jetsl Drell-Yan lepton pair productionà incl. low mass resonancesl di-boson productionà gauge boson self couplingl top quark production„Roadmap“ for first datal 1-10 pb-1:  calibration and alignment with collision data,first measurements (“minimum bias“, …)l ~100 pb-1: refinement of calibration and alignment,re-discovery and measurement of SM processes,first serious sensitivity for new physicsm expected statistics, scaled to 10 TeV (and 100 pb-1)>5∗106 “minimum bias“ events (after trigger)  DESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 16108 jet events (after Trigger)5∗106 direct photon events2.5∗105 Wàlν events2.5∗104   Zàll events>104   Drell-Yan events (small invariant masses)l ~1 fb-1:  sensitivity for Higgs boson discovery, supersymmetry, new resonances (O(TeV))Minimum bias event propertiesl experimental definition of minimum bias events necessaryà usually related to trigger (bias)l several methods to determine charged particle multiplicityà track reconstructionm challenge: access to low pTà hit counting (pixel detector)m determination of secondariesDESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 17à tracklet reconstructionm pairs (triplets) of pixel hits√s=900 GeVCMS-PAS-QCD-09-002√s=14 TeVCERN-OPEN-2008-020Underlying event structurel underlying event (UE) definitionCMS-PAS-QCD-07-003DESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 18à all particle production accompanying the hard scatterà importance à contribution from multi-parton interaction to UEl measurement in transverse regionà relative to jets (or Drell-Yan pair)m distributions shown for 100 pb-1l importance of minimum track pT √s=14TeVCMS-PAS-QCD-07-003Dijet azimuthal decorrelation-09-003l sensitivity to modeling of radiationDESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 19l need to define what a jet is à jet algorithml challenge: jet energy scale determinationCMS-PAS-QCD-√s=10TeVJet shape measurementsl global transverse thrust                    global thrust minorà ½ for homogenous event                               deviation from thrust axis-003DESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 20l sensitivity to modeling of multi-jet eventsà insensitive to jet algorithm and energy scale correctionsà input for MC tuningCMS-PAS-QCD-08-√s=14TeVZ(ee) productionl efficiency determination à “tag & probe” method (data)50 pb-1CERN-OPEN-2008-020CERN-OPEN-2008-020DESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 21l Z à ee signal in 50 pb-1à selection viam 2 electrons ET>15 GeVm soft identification criteriaà accuracy on inclusive cross-section (no luminosity uncert.)m 2-4% (stat) and  2-4% (syst.)200 pb-1CERNCERN-OPEN-2008-020√s=14TeVW(µν) productionl W selectionà single muon with pT>25 GeV and |η|<2m as well as isolation l background suppression by cut on mT:√s=14TeVCMS-PAS-EWK-07-002DESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 22l reconstruction efficiency via “tag & probe“ also for muons(GeV/c)CMS-PAS-EWK-07-002CMS-PAS-EWK-07-002Measurement of µ charge asymmetryl sensitive to u and d quark pdfsl only few systematic uncertainties002CMS-PAS-EWK-08-002√s=14TeVDESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 2310 pb-1CMS-PAS-EWK-08-002CMS-PAS-EWK-08-002W mass determinationl with initial data (only 15 pb-1)à pT(e):    120 ⊕ 117 MeVè energy scale dominatesà MT(µ):    57 ⊕ 231 MeVè recoil modeling dominatesl precision measurement: with higher integrated luminosityCERN-OPEN-2008-020DESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 24CERN-OPEN-2008-020√s=14TeV (estimates shown for 15 pb-1)W/Z+jet productionl important background for many other physics processesà top production, SUSY searches, …/StandardModelFurtherResultsWZJetsDESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 25https://twiki.cern.ch/twiki/bin/view/Atlas/S√s=14TeVDrell-Yan lepton pair productiontop pair background determinationCMS-PAS-EXO-08-001CMS-PAS-EXO-08-001DESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 26l two electrons withET > 30 GeV and |η|<2.5à with identification criteriaà not required:opposite chargeslà from data using eµ events√s=14TeVCMS-PAS-EXO-08-001Rediscovery of top quarkl robust selection criteriaà one isolated muon, pT > 20 GeVm veto on events with further muonsà ≥4 jets, ET > 30 GeVm SISCone, R=0.5m no b-tagging usedl highest vectorially summed transverse momentum of three jets DESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 27CMS-PAS-TOP-09-003à candidate hadronic top decay√s=10TeVCMS-PAS-TOP-09-003Ø next step cross-section measurementTop quark cross-sectionATL-PHYS-PUB-2009-086√s=10TeVDESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 28l dilepton channelà integr. lumin. 200 pb-1l simple object and event selectionà leptons (e,µ) ET > 20 GeVm isolation requiredà jets (Cone 0.4) ET > 20 GeVà ETmiss > 20 GeVl data driven background determinationl signal-to-background ratio between 3.8 (µµ) and 5.5 (eµ)“re-discovery”of Standard ModelDESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 29(and more…)Search for the Higgs boson at LHCEur.Phy.J.C60:543-583,2009arXiv:0903.4001 [hep-ex]DESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 30CERN-OPEN-2008-020Examples of Higgs signalsHàγγ Hà4lCERN-OPEN-2008-020CMS-PAS-HIG-08-001HàττDESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 31+2jets+1jet1 fb-1CMS-PAS-HIG-08-006HàWW*√s=14TeVDiscovery potential Higgs bosonCERN-OPEN-2008-020DESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 32l for an integrated luminosity of 2 fb-1 (√s=14 TeV)à 5σ sensitivity for discovery:      143 GeV < MH < 179 GeVà expected range of exclusion (95% C.L.)on MH:  115 to 460 GeVm studies valid only for  L ≥ 2 fb-1m not all relevant channels have been included √s=14TeVsearch for new physics DESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 33beyond the Standard ModelOn the way to Terra Incognita …http://www.interactions.org/imagebank/search_detail.php?image_no=OT0103DESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 34lhttp://www.interactions.org/imagebank/search_detail.php?image_no=OT0103Recipe (checklist) for discoveriesl to find a deviation is easy …à to prove that it stems from new physics is harderà simple-minded recipem find variable(s) discriminating between signal and backgroundm cut away most background (maximing signal significance)m estimate remaining background events à look at yield …need to care/worry aboutDESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 35là is the detector behavior really understood ?m efficiencies, fake rates, energy/momentum scales, non-Gaussian resolution, …è try to obtain as much information as possible from dataà is the SM prediction really understood ?m cross-section, kinematic distributions, underlying event, …èmust know sources for uncertainties on theseCompositenessl present exclusion limit (Tevatron)   Λ+: ~2.7 TeVCMS-PAS-SBM-07-001DESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 36√s=14TeVResonances in dijetsl present exclusion limit (Tevatron) dijet mass:   ~ 0.8 TeVCMS-PAS-SBM-07-001DESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 37√s=14TeVDrell-Yan lepton pair productionCMS-PAS-EXO-08-001Standard ModelDESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 38l two electrons withET > 30 GeV and |η|<2.5à with identification criteriaà not required:opposite charges√s=14TeVSearch for new gauge bosons: Z‘CMS-PAS-EXO-08-001Standard Model… and moreDESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 39l two electrons withET > 30 GeV and |η|<2.5à with identification criteriaà not required:opposite charges√s=14TeVSearch for new gauge bosons: Z‘CMS-PAS-EXO-08-001CERN-OPEN-2008-020DESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 40l Z‘ discovery potentialm 2 electrons (pT > 65 GeV)à exclusion limit (95% C.L.)~ 1 TeV by Tevatronl two electrons withET > 30 GeV and |η|<2.5à with identification criteriaà not required:opposite charges√s=14TeVMisalignment and discovery potentialCERN-OPEN-2008-020DESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 41l invariant µµ mass distribution for several misalignment scenariosm Z’χ model √s=14TeVl 1-CLb value vs. integrated luminositym for Z’χ modelDiscovery potential for W’CERN-OPEN-2008-020DESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 42l 5σ discovery potentialà systematics consideredm generator (higher orders, pdf)m instrumental (energy scale and resolution of lepton and jet, impact on missing ET) √s=14TeVCERN-OPEN-2008-020Supersymmetryl mSUGRAà one model for the symmetry breakingà defines benchmark pointsDESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 43Inclusive SUSY searchl event selectionà lepton(s): electron or muon (|η|<2.5 and pT > 10 GeV)à jets: cone algorithm (R=0.4, |η|<2.5 and ET > 20 GeV)à ETmiss: using calorimeter cells, adding muon contribution84DESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 44ATL-PHYS-PUB-2009-084√s=10TeVDiscovery reach for SUSYATL-PHYS-PUB-2009-084DESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 45l inclusive search (√s = 10TeV and 200 pb-1)à using 0,1 or 2 leptons and up to 4 jetsà discovery of squarks and gluinos with masses up to 600-700 GeV possible (case of R-parity conservation) √s=10TeVExtra dimensions / mini black holesl Universal extra dimensionsà analysis similar to inclusive supersymmetry search-PHYS-PUB-2009-084√s=10TeVl mini black holes: spectacular signaturespossibleà selectionm Σ|pT| > 2.5 TeV1 lepton with p >50 GeVDESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 46CERN-OPEN-2008-020√s=14TeVATL-m ≥ Tà 5σ discovery potentiall ADD extra dimen-sionsà search for mono-jetsCMS-PAS-EXO-09-013√s=10TeVA vision towards initial results …ATL-PHYS-CONF-2008-015DESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 47f(time) (a.u.)Summary and outlookl first LHC physics run in 2010à √s = 7 TeV (with possible step-up to 8-10 TeV)à integrated luminosity of 200 – 300 pb-1l ATLAS and CMS are ready and well prepared to exploit this initial dataà extensive commissioning (e.g. muons from cosmic rays)DESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 48l threefold approach to initial data takingà refine detector understanding with collision dataà establish properties of pp collisions at 7 TeV and beyondm ‘re-discovery’ of the Standard Modelà search for new phenomena and surprisesm first possibility to move beyond Tevatron sensitivityThe very final slidel hope to be soon in a situation where we know that there are a lot of unknowns to be exploredDESY Theory Workshop “Collider Phenomenology”  Sep. 29 - Oct. 2nd, 2009 Stefan Tapprogge, Johannes Gutenberg-Universität Mainz Seite 49

LHC physics with early data

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