E/gamma Trigger Efficiencies

Sam Harper

RAL

Trigger Performance Meeting

17/05/10

2/14

E/g HLT 101: Basic Trigger• core e/gamma triggers are a

supercluster with ET > X matched to a L1 Seed– L1 is a trigger tower with ET > X

• electron triggers additionally require a PM match– note most “electron” triggers are

not electrons at HLT, they are SC + PM

– only EleId + TrackIsol triggers run electron tracking (which is different to RECO…)

• Currently L1 trigger almost completely drives the eff curve for |η| < 2.1

L1 Trigger Accept

Match SuperClus to L1 seed

ET filter (SC ET, w.r.t 0,0,0)

Pixel Matching Step

Hcal Isolation Filter

Spike Filter (E1/E9<X)

end of pho triggers

not currently enabled

HLT Starts

additional ele trig step

note: that L1 η/φ is fairly coarse

3/14

Analysis Details• data: /MinimumBias/Commissioning10-GOODCOLL-v9/RAW-RECO

– runs: 133874, 133877, 133881,133885, 133928• good lumi sec in backups

– spike cleaning: E1/E3x3 <0.9, bx = 1 or 1786

• MC: /MinBias/Spring10-START3X_V25B_v1/GEN-SIM-RAW

– RECOd in CMSSW_3_5_7, START3X_V26A

• HLT: – /cdaq/physics/firstCollisions10/v5.1/HLT_7TeV_HR/V1– using CMSSW_ 3_5_7_p2 , GR10_H_V5

• https://twiki.cern.ch/twiki/bin/viewauth/CMS/HowToInstallONLINErelease

– not the menu/release that the data were taken with but the menu the next data are being taken with

– MC: HLT_GRun in 3_5_7, START3X_V27– FYI: all menus can be found at:

• http://cms-project-confdb-hltdev.web.cern.ch/cms-project-confdb-hltdev/browser/

• online is under ORCOFF, development on HLT Development

4/14

Previous Work

• HLT Eff. to be shown to be 100% for |η| <2.1– therefore L1 completely dominates turn on curve– S. Harper: http://indico.cern.ch/conferenceDisplay.py?confId=93821

• Large amount of work done on understanding L1 Efficiency and turn on curves by LLR and Wisconsin groups in L1 DPG– J. Efrons: http://indico.cern.ch/conferenceDisplay.py?confId=94122 – C. Broutin: http://indico.cern.ch/conferenceDisplay.py?confId=92206

5/14

Efficiency Method

• simply take efficiency as number of SC passing HLT (or filter) / total number of SC– after applying spike rejection and correct bx of course

• cross-checked biasness of sample by selecting only those events which pass HLT_MinBiasBSC or HLT_MinBiasHcal– looks okay…

6/14

L1+HLT Eff Barrel: Pho10

• L1 efficiency drives the curve…• bad MC agreement for all data, good agreement with

H/E<0.05 cut is applied

all SC H/E<0.05

7/14

L1+HLT Eff Endcap: Pho10

• again better MC/data agreement once H/E cut on• different turn on curves for data/MC

– LLR group shown that L1 not efficient for SC where energy is spread over multiple trigger towers

• typical of jets, less typical of electrons

all SC H/E<0.05

8/14

L1+HLT Eff Endcap: Pho10

• Shown by LLR that L1 trigger efficiency drop is due to SC being spread out over multiple trigger towers

• sigmaIEtaIEta < 0.0275 cut improves turn on but clus = 1 is better– H/E does nothing to turn on– likewise EM isolation

9/14

Eff vs η/φ

• all plots have a SC

ET>10 GeV and H/E<0.05 cut applied

• no real surprises here

barrel

endcap

9/14

10/14

HLT Clustering

• my last talk implied this was ~100% – this is not quite true as was starting from L1 Match filter– sometimes the HLT fails to reconstruct a SC, this is almost the only way to fail the

L1 match (the matching is generous…)

• In EB HLT requires seed ET > 1.5 GeV, RECO ET > 1 GeV

• results in small inefficiency for jets

Eff to get HLT SC L1 Match given RECO SC L1 Match

11/14

Ele Trigger Eff

• Efficiency for ecal driven GsfEle electrons to pass Ele10_LW, having passed Pho10– 100% for |η|<2.1

– disagreement in MC

12/14

Ele10LW Eff vs φ

• φ dependence of MC points to overly pessimistic startup conditions– I used START3X_V27 tag, is this correct?

13/14

Ele10LW Eff vs η

• hard to tell with stat. but don’t see a clear ET dependence on PM efficiency

• need more stat to check but likely eff as a function of ET should suffice– note real ele efficiency

will be different…

14/14

Conclusions

• measured L1+HLT efficiency for Photon and Electron triggers– rate is completely driven by L1– shower shape cuts help improve

turn-on• new RCT calibrations are being

tested that will help this

– some differences with MC observed

• currently main sources of inefficiency in data are understood

H/E<0.05

H/E<0.05

|η|<1.442

1.56<|η|<2.5

Pho10 Eff

Pho10 Eff

14/14

15/14

Backups

good lumisec used:• '133874:166-133874:814', '133874:817-

133874:875', '133875:1-133875:20', '133875:22-133875:49', '133877:1-133877:1640', '133877:1643-133877:1997', '133881:1-133881:71', '133881:74-133881:223', '133881:225-133881:562', '133885:1-133885:132', '133885:134-133885:728', '133927:1-133927:57', '133928:1-133928:645',

16/14

E/g HLT 101: Glossary• ET: super cluster ET w.r.t to 0,0,0

• LW PM: large window pixel matching– concerns about beamspot stability in very early running so very loose

pixel matching windows initially– currently whats running for electron triggers

• SW PM: startup window pixel matching– slightly tighter pixel matching requirements which will be introduced

around 1E31 once we have shown that it doesn’t impact electron efficiency

• Electron Tracking:– only done for EleId + Track Isolation Trigger– CTF tracking algo not GSF– less forgiving on missing hits, not as efficient as RECO CTF tracking

• HCAL isolation: – actually more H/E, sum of rec-hits in cone of 0.15 – not currently used

17/14

SW vs LW

• first look at startup pixel match windows in data

18/14

L1+HLT Pho10 Eff: ID Cuts

σiηiη < 0.0275

σiηiη < 0.0275

H/E < 0.05

Isol EM < 3 GeV

σiηiη < 0.0275

H/E < 0.05

Isol EM < 3 GeV

Isol Had < 1 GeV

σiηiη < 0.0275

H/E < 0.05

19/14

Ele Trigger Eff with EleID

• applied HEEP ID to electrons to see if MC efficiencies are changed

20/14

C. Broutin: L1 DPG 22/04/10

21/14

C. Broutin: L1 DPG 22/04/10

22/14

J. Efron: L1 DPG 06/05/10

23/14

HLT ET Turn vs RECO SC ET

• Eff of ET filter w.r.t L1 Match– this should be close to a step function

• for SC with ET > 10 GeV

barrel endcap