Photon performance with early 7TeV data
1) photon performance (using f249): data/MinBias MC2) comparison: data / MinBias MC / +jets MC
D. Zhang (IPAS&USTC) &
N. Panikashvili (UM)
Data / MC
• Data:– Run: (f249)153134, 153136, 153159,
153200– LHC stable beam– Pixel SCT green– Same lumiblocks as e/ GRL
• MC:– 105001, Pythia_Minbias– reconstruction tag r1210 (using DB
release 9.6.1)
Trigger & PV selection• Trigger: Require data and MC passing L1_MBTS_1_1
(require a 1-hit-coincidence)• Primary vertices: select event with a good primary
vertex which has at least 3 tracks
Data MC
Total N 3.7M 10M
Efficiency trigger 75% 99%
Efficiency PV 95.6% 97.6%
N events 2.6M 9.6M
Object selection electron:
Author 1 or 3 isEM is tight p
T>5GeV, |η|<2.47 and exclude crack region [1.37, 1.52]
N of pixel hits >1, N of SCT hits > 6 muon (Staco):
combined muon p
T> 5GeV, |η|<2.5
N of pixel hits >1, N of SCT hits > 6 photon:
pT(γ) >5GeV, |η|<2.37 and exclude crack region [1.37, 1.52] ΔR > 0.2 between leptons and γ isEM is loose, tight
jet: AntiKt4H1Topo Jet p
T>20GeV, |η|<3.1
remove jets overlapped with tight electron or tight photon in cone 0.4 remove jets: jet N90 ≤ 2 & SamplingMax = 17
Photon cut flow efficiency
SelectionData MC
All Author = 4 Author = 16 All Author = 4 Author = 16
Overlap removal 11356 5901 5455 90653 49797 40856
isEM loose 2499 (22%) 1508 1007 24449 (26%) 15204 9245
isEM tigth 358 (3.1%) 189 169 5042 (5.6%) 2859 2183
isEM tightIso 5 (0.04%) 2 3 87 (0.096%) 52 35
Cut efficiency with respect to previous cut Overall efficiency
photon pT: all, Author = 4, Author = 16
Overlapremoval
isEM - loose
isEM - tight
photon isEM - loose isEM - tight
all
Author = 4
Author = 16
events with loose photonsJet pT Leading jet pT
Jet multiplicity Jet sum ET
events with tight photonsJet pT Leading jet pT
Jet multiplicity Jet sum ET
MET/sumETisEM - loose isEM - tight
events with loose photons
Δφ (leading jet, MET)Δφ(Leading photon, MET)
Meff
events with tight photons
Δφ (leading jet, MET)Δφ(Leading photon, MET)
Meff
• Compare: – Data: integrated luminosity 347.1μb-1 – MinBias MC: (MinBias) = 48445 μb +jets MC: (+jets) = 1.41 μb
• Events requirement:– At least one jet with pT>20GeV
– One loose/tight photon: pT>10GeV, ||<2.3
events with loose/tight and at least one jet
isEM - loose
isEM - tight
events with tight and at least one jetLeading jet pTJet pT
HTMET
events with tight photons and one jetΔφ (leading jet, MET)Δφ(photon, MET)
Δφ(photon, jet)
Conclusions
• Agreement (in shape of the distributions) between Data/MC
• Continue check performance with new runs
• High fake photons rate in the low pT range