April Analysis

https://twiki.cern.ch/twiki/bin/view/CMS/SWGuideEWKVPlusJets package is being used now, here is what I understand:

Pick the package from: ElectroWeakAnalysis/VPlusJets/ and goto test, cmsRun ZllJetsAnalysis_cfg.py

• For Z-->ee Collection: Picks "gsfElectrons" with '((abs( caloPosition.eta ) < 1.4442) | (1.560 < abs( caloPosition.eta ) < 2.5)) & (( caloEnergy * sin( caloPosition.theta ) ) > 20.0)'), ZToEE filter has mass window from 60-120. and then keep only 1 of largest pt candidates.
• For Jet Collection:
  • CaloJetCollections: Pick iterativeCone5CaloJets || sisCone5CaloJets || ak5CaloJets and clean them i.e. see if there is any gsfElectrons within a cone of DeltaR=0.3 around the jet axis.
  • CorrectedCaloJetCollections: L2L3Corrections_Summer09_7TeV corrections are applied and pick L2L3CorJetIC5Calo || L2L3CorJetSC5Calo || L2L3CorJetAK5Calo and clean them as said above which gives ak5CaloJetsCor collection but that is again cleaned , don't know why.
  • GenJetCollections: do the same as CaloJetCollections i.e. use gsfElectrons collection to clean *5GenJets ?
  • PFJetCollections: same cleaning step of *Cone5PFJets with gsfElectrons
  • JPTJetCollections: ?
  • TagJetCollections: ?
• Fill tree and start analyzing it

Analysis: Start with Z+1Jet selection:

• Fill Z mass, pt, Y, phi:
• Fill Z daughters at the same time
  • Daughter selection: see Robust Loose Cuts for CMSSW33X optimization.

 
   # variables H/E sigmaietaieta deltaphiin deltaetain e2x5/e5X5 e1x5/e5x5 isoTk ecalTk hcalTk(barrel/endcap)
    #Robust Loose Cuts
    #V00 CMSSW16X optimization 
    #V01 CMSSW22X optimization
    #V02 CMSSW33X optimization
    robustlooseEleIDCutsV00 = cms.PSet(
        barrel = cms.vdouble(0.115, 0.014, 0.09, 0.009, -1, -1, 9999., 9999., 9999.),
        endcap = cms.vdouble(0.15, 0.0275, 0.092, 0.0105, -1, -1, 9999., 9999., 9999.)
    ),
    robustlooseEleIDCutsV01 = cms.PSet(
       barrel = cms.vdouble(0.075, 0.0132, 0.058, 0.0077, -1, -1, 9999., 9999., 9999.),
       endcap = cms.vdouble(0.083, 0.027, 0.042, 0.01, -1, -1, 9999., 9999., 9999.)
    ),
    robustlooseEleIDCutsV02 = cms.PSet(
       barrel = cms.vdouble(0.05, 0.0103, 0.8, 0.00688, -1, -1, 7.33, 4.68, 9999.),
       endcap = cms.vdouble(0.0389, 0.0307, 0.7, 0.00944, -1, -1, 7.76, 3.09, 2.23)
    ),
    robustlooseEleIDCuts = cms.PSet(
       barrel = cms.vdouble(0.05, 0.0103, 0.8, 0.00688, -1, -1, 7.33, 4.68, 9999.),
       endcap = cms.vdouble(0.0389, 0.0307, 0.7, 0.00944, -1, -1, 7.76, 3.09, 2.23)
    ),

• If there is a jet with more than 10GeV , pick it.
• find dPhi between Z and leading jet if it is > 2.94 select the events
• find ratio of second jet pt to Z pt, if it is < 0.2, then select events.

I have compiled everything in a webpage : http://lovedeep.web.cern.ch/lovedeep/work10/April/

TO DO: Add Jet plots for gen level and signal to background ratio check

Jet Studies

We have three jet species to choose from namely particle flow, calorimeter and track jets. We here try to see their relative affect on the Z+Jet studies. First we show the kinematics and multiplicity for all the jets in the events which posses at least one Z boson (with all the selection criteria satisfied). We see that the number of calojets is significantly greater than the PF jets especially at the low energy. This is probably due to formation of many small calojets beacause of clustering inefficeincy.

FIGSET:1

To make the things simple, we look at the Z+1jet candidate events. The selection is defined above in the analysis section, and just to look into the inherent differences between the calo and particle flow approaches we are applying same threshold for both kind of jets. The figures below show the plots for the kinematics, response, correction factor, z-jet balance. The link below point to same plots for made using higher pT thresholds for jet selection.

FIGSET:2

Now since the standard pT thresholds for the jet selection are not same for calo and the pF jets, we try to see how this asymmetrical selection affect their counting. Figures below show the jet eta and jet phi distributions in 1 jet events selected using pT thesholds of 15 and 30 GeV for PF and Calo respectively. We also present the event yield and Z-Jet balancing plots.

FIGSET3

Finally we come upon to study the affect of the Jet Id in both the cases. Below we present the same plots as above but with the respective id criteria applied for the calo and pf jets.

FIGSET4

Now since we have studied both the inherent contrasts and the ones coming from different selection criteria, we look at the Z+nJet events. Plots below show the absolute yield in the bins of inclusive jet multiplicity for both the calo and particle flow jets. We also show the kinematics for 1st, 2nd and 3rd leading jets in the selected Z+(1,2,3) events.

FIGSET5

*Conclusions: *

Notes:

We want to optimize Jet Pt threshold so to avoid UE. ( UE: all the additional activity accompanying the hard scattering component of the hadron-hadron collision http://www.isv.uu.se/thep/courses/QCD/QCD_presentation_Martin.pdf )

-- LovedeepKaurSaini - 25-Mar-2010