Status of Muon Trigger Efficiency Measurement for ICHEP Benedikt Hegner, Benjamin Klein, Yvonne Küssel, Patricia Lobelle, Markus Marienfeld, Rahmat Rahmat, Laria Redjimi, Jason Slaunwhite, Sinéad Walsh Trigger Performance Group meeting 21 June 2010

Plans Goal Goal: provide muon trigger efficiency measurement for top analyses Based on minbias & jet trigger data See status reports presented by Benjamin (27 May, slides) and Yvonne (15 June, slides) — See status reports presented by Benjamin (27 May, slides) and Yvonne (15 June, slides)slides — Results collected in our twiki page: Step1: ~21 May Total efficiency with error large enough to cover any observed variation in eta/pt Step2: ~week of 7 june Coarse parameterisation of the trigger efficiency Step3: ~end of june Tag & probe with Z->  from data 2  Roadmap as shown in Jason's talk on 29th of April (slides)slides We are close to the initial schedule (slowed down by limited statistics)

Datasets  JetMETTau triggered samples /MinimumBias/Commissioning10-SD_JetMETTau-v9/RECO Runs: , , , , , , , , , , , , , /JetMETTau/Run2010A-May27thReReco_v1/RECO Runs: , , , , , , , , , , , , Skim – At least one muon of any kind (global/tracker/standalone) with Pt>5 GeV – Scraping Veto && Primary vertex filter – HltPhysicsDeclared (next iteration only relying on good LS)  After Skimming: events ~ 17 nb -1 3

Muon selection & efficiency definition Muon selection as close to the top mu+jets reference as possible with the current available statistics isGlobalMuon && isTrackerMuon Chi2< 10 NvalidMuonHits>0 d 0 <0.2 N hits>=11 RelIso <0.05  No iso cut applied now pT > 5GeV Eta<2.4 — Currently studying more muon clean-up cuts —Cross check with what’s being done in Muon POG & VBTF Efficiency definition  fraction of good selected muons matched to HLT muons in dR<0.2 Study HLT_Mu5 Study HLT_Mu5 - HLT_Mu9 when we have more statistics 4 Matching ~99% efficient

HLT_Mu5 Efficiency vs pt,  5 Overlap CSC DT

6 Efficiency vs some cut variables Data vs MC Jet definition Jet definition: Ak5 caloJets Et>30 EmEnergyFraction>0.01 N90hits>1 fHPD<0.98 Jet definition Jet definition: Ak5 caloJets Et>30 EmEnergyFraction>0.01 N90hits>1 fHPD<0.98 Jet multiplicity Jet multiplicity

Additional cuts applied (recommened by Muon POG) on top of the reference selection to reject punch through and decays in flight S.Walsh 7 Reference selection On slide 4

8 S.Walsh Some more efficiency plots vs cut variables, comparing this new selection with the old one

Comparison with ttbar MC Muon trigger efficiency for high-pt muons from ttbar Non-isolated muons to increase statistics, Average efficiency is 94% Average efficiency is 94% Chi2< 10 d 0 <0.2 N hits>=11 pT > 10GeV Eta<2.4 9 Sample: /CMSSW_3_6_1/RelValTTbar/GEN-SIM- RECO/MC_36Y_V7A-v1/ - Prompt ttbar muons are different from the non-prompt muons that exist in the data we've collected so far - We don't necessarily expect the efficiency to be the same without clean up cuts - Studies of clean-up cuts under investigation J.Slaunwhite

General recommendations to be used in top analyses Triggers used in top analyses Triggers used in top analyses - Muon channels: HLT_Mu9 - Electron channels: HLT_Photon10_L1R up to now, HLT_Photon10_Cleaned_L1R from now on (switch to HLT_Photon15_Cleaned_L1R when it has to be prescaled) Should we in addition request any other bits (e.g. BSC beam-halo veto on 36||37||38|39 etc ? Should we request the trigger also in MC or not ask for the HLT bit in MC, but just apply a global scale factor for the inefficiency observed in data (inclusively) ? 10

Summary HLT_Mu5 efficiency measurement available Results are being posted in Reasonable agreement with MC Will compare with similar studies performed in other groups (Muon POG, VBTF) to understand possible differences … 11