Jet Validationof

Summer11 MC

Artur ApresyanCaltech

Joanna WengETH Zurich

Kittikul KovitanggoonTexas Tech University

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Summer11 wrt Spring11_S2

• The datasets are • Summer11 MC processing with CMSSW_4_2_2

• /TT_TuneZ2_7TeV-pythia6-tauola/Summer11-PU_S3_START42_V11-v2/GEN-SIM-RECO

• Spring11 MC processing with CMSSW_4_1_4• /TT_TuneZ2_7TeV-pythia6-tauola/Spring11-PU_S2_START311_V2-v2/GEN-SIM-RECODEBUG

• Both datasets have inTime and OOT PU, but the Spring11 sample mistakenly was produced with 25 ns bunch-spacing• In both samples, the inTime and OOT PU have the “Flat10” distribution• https://indico.cern.ch/getFile.py/access?contribId=3&resId=1&materialId=slides&confId=136336

• Summer11 has 50 ns bunch-spacing

• Details about various PU configurations are at:• https://twiki.cern.ch/twiki/bin/viewauth/CMS/PileupInformation 2

Generator Level Jets

• The jet parameters look identical on both Summer11 and Spring11_S2• Generator level includes only particles from primary collision, no pile-up

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Summer11Spring11

# of jets, |η|>1.3, pT>10 GeV

Reco jet MultiplicityReco jet Multiplicity

• This and the following slides will show comparison for AK5 CaloJets

• Conclusions for other types of jets are the same

• Higher jet occupancy in Spring11_S2, which is expected from OOT PU that is more pronounced in Spring11 (25ns pileup)

• Number of jets is higher in Spring11_S2 sample, but they are mostly soft jets from different OOT PU 4

Summer11Spring11

# of jets, |η|≤1.3, pT>10 GeV Jets Pt

Jet pT scale (pTcalo/pT

gen)

• Jet scale in Spring11_S2 is higher than that in Summer11 in all detector regions• Most pronounced in jets up to ~100 GeV• The difference is bigger in Endcaps, and most pronounced in the HF region

• Again, expected from 25 ns OOT PU in Spring11_S2

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PT scale, |η|≤1.3

Summer11Spring11

PT scale, 1.3<|η|<3.0 PT scale, 3<|η|<5.0

Jet Eta and Phi distributions

• Flat in Phi, the “horns” in eta are more pronounced in Spring11_S2 likely due to 25ns

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Jets η, PT>10 GeV Jets φ, PT>10 GeV

Summer11Spring11

Summer11 VS Summer11 VS Spring11_S1Spring11_S1

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Summer11 wrt Spring11_S1

• The datasets are • Summer11 MC processing with CMSSW_4_2_2

• /TT_TuneZ2_7TeV-pythia6-tauola/Summer11-PU_S3_START42_V11-v2/GEN-SIM-RECO

• Spring11 MC processing with CMSSW_4_1_4• /TT_TuneZ2_7TeV-pythia6-tauola/Spring11-PU_S1_START311_V1G1-v1/AODSIM

• Here we are comparing to Spring11_S1 sample which has NO OOT PU wrt Summer11 sample.• Summer11 sample is the same as shown on previous pages, with 50ns OOT PU

• Detailed comparisons at:• http://highenergy.phys.ttu.edu/~keng/validation/plots/TT_Summer11_wrt_Spring11_S1_area/

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# of jets, |η|>1.3, pT>10 GeV

Reco jet MultiplicityReco jet Multiplicity

• This and the following slides will show comparison for AK5 CaloJets• Conclusions for other types of jets are the same

• Slightly higher jet occupancy in Summer11 samples, effect of OOT PU

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Summer11Spring11

# of jets, |η|≤1.3, pT>10 GeV Jets Pt

Jet Eta and Phi distributions

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Jets η, PT>10 GeV Jets φ, PT>10 GeV

Summer11Spring11

Jet pT scale (pTcalo/pT

gen)

• Jet scale in Summer11 is higher than that in Spring11_S1, in all detector regions• Expected for barrel and endcap, but not immediately clear why different in HF

• HF energy reconstruction is done with 2TS, should be insensitive to 50ns OOT PU• Maybe PileUp (inTime) configuration is different between S3 and S1?

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PT scale, |η|≤1.3

Summer11Spring11

PT scale, 1.3<|η|<3.0 PT scale, 3<|η|<5.0

Energy in subdetectorsEnergy in subdetectors

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Summer11Spring11

Energy in EB Energy in EE

Energy in HB Energy in HE Energy in HF

Unexpected difference in HF

Jet pT response (pT

corrected/pTgen)

• After applying the L2L3 jet energy corrections the differences are not as large between two samples

• But it is still not clear why there is difference in previous page…

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PT scale, |η|≤1.3

Summer11Spring11

PT scale, 1.3<|η|<3.0 PT scale, 3<|η|<5.0

Jet Validation of Spring 2011

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CMSSW Release Validation status

4_2_2 Pass

4_3_0_pre2 Pass

4_3_0_pre4 Pass for Calo and JPTFail for JPT

Change in JPT algorithm

4_1_6 Pass

4_2_3 Pass

4_3_0_pre4

• This discrepancies are understood to be caused by a change in JPT algorithm.• Starting from some 4_3_0_preX we use UseZSP = cms.bool(False) in

agreement with the new JEC structure for JPT.• ZSP corrections should go into L1JPTOffset. Staring in 4_3_0_pre6 release.

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4_3_0_pre44_3_0_pre2

• The energy change for the JPT algorithm.

PT scale, |η|≤1.3 PT ratio

Conclusions• The Jet validation for normal release is moving smoothly

•Spring11_S2 MC has more jets than Summer11 MC, but they are mostly soft jets from different OOT PU (25 ns OOT PU in Spring11_S2 and 50 ns OOT PU in Summer11)

• Jet pT response is higher in Spring11_S2 than Summer11. This again is expected from different OOT PU

• Generator level jets are identical in both datasets

• Spring11_S1 sample looks OK in general, but some features need further investigatio

• Response is OK, Spring11_S1 can likely be used for analysis, we are following this up with HCal group

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