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Trigger efficiency with UED SS dimuon events. F. Marinho. Overview. UED Model reminder Motivation for trigger studies Trigger efficiency vs muon P T Trigger Paths ( Leptonic & Hadronic ) Background. The UED model.
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Trigger efficiency with UED SS dimuon events F. Marinho
Overview • UED Modelreminder • Motivation for triggerstudies • Trigger efficiency vs muon PT • Trigger Paths (Leptonic & Hadronic) • Background
The UED model • Allparticles are allowed to propagate in the extra dimension • KK numberconservation UED pairproductionand LKP • Predictstheproductionofthe N=1 modesat LHC energies • Interestingphenomenology. In some aspects similar to SUSY models
ThemUEDmodel Ecm = 7 TeV • Parameters: 1/R, • HighXSectionvaluesdependon 1/R • PT distributions in thelow GeV range • Triggerstrategyshouldnotcutthosemuons Reconstructed
Data sets • Used CMSSW_3_3_6: Fastsimulationwithstartup setup + trigger • EventsgeneratedwithPythiaonly • UED ssdimuons: 1/R: 300, 500, 700, 900, 1100 ~35000 events per point • ttbar inclusive events225000 events
MuonReconstruction • Reconstructionefficiency as a functionof PT • Muonsatlow range are alreadysuppressed in thereconstruction Muonrequirements: Prompt, Global, MC matched • Triggeralgorithmsshouldnotincreasetheseeffectsabove7GeV
TriggerEfficiency • Throughoutthistalk: • Only Global Muons are used • Trigger denotes theHLT trigger path used • Efficienciesevaluated for leadingandnext to leadingmuons • Bothmuonsreconstructed: 80% ofsignalkept
SingleMuon Paths • HLT Paths highlyefficient for signal • Low PT range notsignificantlyaffectedbytriggercutsup to 5 GeV • PT cutsshouldbe< 7GeV keepingefficiencyabove 80% for thenext to leadingmuon
Dimuon Paths • Highefficiency paths for signal • Dimuon paths have similar effectsonleadingandnext to leadingmuons
MET Paths • Signaleventswithdistinct MET signature • Twolightestparticles • Muonsdistributions are notdistorted
Jet Paths • Signaleventswithdistinct Jet+MET signature • Almostalleventswereaccepted • Muondistributions are recovered • Jet cuts are veryloose in these HLT Paths • More interesting to cutonnumberofjets (offline)
Background ttbar • 5%ofeventswith SS dimuon • Suppressiondue to RECandcharge requirement • Lead muonsfromW’sandb’s • Next to lead muonsfromhadronic • No isolationorothercuts are applied
ttbar - Muon Paths • Distributions similar to signal • Butefficiencies are lower
ttbar – Dimuon Paths • Similar distributions • Lowerplateaus
ttbar – MET Paths • Low PTcorrelation • Good path for robustnesscheck? • Background highlysuppressed • Use as offlineselectionvariable
ttbar - Jet Paths • No PTcorrelation • Good path for robustnesscheck? • Backgroundpartiallysuppressed • Use as offlineselectionvariable
Summary • SS dimuonanalysispromisingalreadyat startup possible to scratchcurrent1/Rlowerlimit • Avoidacceptanceeffects for muondistributionsatleastonofflinelevel • Muontriggers for startup data employed. • Considerhadronic Paths for robustnesspurposes. • MET andJets are interesting as offlineselectionvariables.
Next • Offlineselection • Improve background studies • Determine yieldsat 7 TeV • Yieldsvsmodelparameters • Sameexercise for otherleptons (anyoneinterested???)