Exclusive tt analysis using full run II CMS data

Overview

On this page:

Usefull Links

• Analysis twiki: ExclusiveTop
• Exclusive ttbar talk (LHC WG on Forward Physics and Diffraction): link

Data and MC samples

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Show available MC signal samples  Hide available MC samples 

Show available Data samples  Hide available Data samples 

NTuple production

proton reconstruction and Ntuplizer

Production is performed using TopLJets2015 analysis package which use PPS reconstruction data. The full instruction for simulating the forward protons can be found in TaggedProtonsDirectSimulation twiki. The configuration file is attached (ProtonReco.zip).

scram project CMSSW CMSSW_10_6_10
cd CMSSW_10_6_10/src
cmsenv

git cms-init
git remote add ctpps git@github.com:CTPPS/cmssw.git
git fetch ctpps pps_zx_mc_10_6
git checkout -b test ctpps/pps_zx_mc_10_6
git cms-addpkg IOMC/EventVertexGenerators SimCTPPS/Generators
scram b -r -j8

# ---- Settings for TopLJets2016 ----

#EGM id
git cms-merge-topic cms-egamma:EgammaPostRecoTools
scram b -j8

#B-fragmentation analyzer
mkdir TopQuarkAnalysis 
cd TopQuarkAnalysis
git clone -b 94x https://gitlab.cern.ch/psilva/BFragmentationAnalyzer.git
cd -
scram b -j8

#TopLJets package
git clone https://github.com/michael-pitt/TopLJets2015.git -b 106_protonreco
cd TopLJets2015
git remote add upstream https://github.com/pfs/TopLJets2015.git
git checkout 106_protonreco
cd -
scram b -j8
# --------------------------
cd ../..

The following lines should be executed (CMSSW should point to your CMSSW setup as explained here): The code will run both PPS reconstruction and ntuplizer. Option of exclude PU protons from reconstruction is doPUProtons=False. To switch off event skimming (defined in MiniAnalyzer.cc) you can set applyFilt=False.

cd ${CMSSW}/src
eval `scram r -sh`
cd -
cmsRun ${CMSSW_BASE}/src/TopLJets2015/TopAnalysis/test/runMiniAnalyzer_cfg.py runOnData=False era=era2017 inputFile=file:miniAOD.root outFilename=nanoAOD.root maxEvents=-1 runProtonFastSim=120 noParticleLevel=True

NOTE: several options should be considered:

• miniAOD w/o proton reco: The proton simulation should be executed, this is done with runProtonFastSim=120 option.
• miniAOD with protonreco: No need to proton simulation, just define the inputs properly: RecoProtons=True
• data: for data use: XXXXXX
• proton simulation: if you wish not to use the PU protons you can add doPUProtons=False option

to process miniAOD, one should change the collection name to: cms.InputTag("prunedGenParticles")

Making validation plots

miniAOD

Helper: set up few Aliases for shorter Draw commands:

Events->SetAlias("genpar","recoGenParticles_prunedGenParticles__PAT.obj")
Events->SetAlias("PUproton","recoGenParticles_genPUProtons_genPUProtons_HLT.obj")
Events->SetAlias("proton","recoForwardProtons_ctppsProtons_singleRP_CTPPSTestAcceptance.obj")
Events->SetAlias("lhe","LHEEventProduct_source__LHEFile.obj.hepeup()")

• To plot top - anti-top invariant mass from the samples, either directly from tops or from the protons

Events->Draw("sqrt((genpar.energy()[2]+genpar.energy()[3])**2-(genpar.px()[2]+genpar.px()[3])**2-(genpar.py()[2]+genpar.py()[3])**2-(genpar.pz()[2]+genpar.pz()[3])**2)")
Events->Draw("2*sqrt( (6500.-genpar.pz()[0])*(6500.+genpar.pz()[1]))")
Events->Scan("lhe.IDUP :lhe.ISTUP")

• To plot proton p_Z vs reconstructed p_Z (similarly can be made for ξ):

Events->Draw("proton.pz() : genpar.pz()[0]","proton.pz() > 0")

For more variables see reco::ForwardProton or TaggedProtonsGettingStarted.

nanoAOD

root -l  nanoAOD.root
TTree * tree = (TTree*)analysis->Get("data")
tree->SetAlias("Et1","sqrt(gtop_pt[2]*gtop_pt[2]*cosh(gtop_eta[2])*cosh(gtop_eta[2])+gtop_m[2]*gtop_m[2])")
tree->SetAlias("Et2","sqrt(gtop_pt[5]*gtop_pt[5]*cosh(gtop_eta[5])*cosh(gtop_eta[5])+gtop_m[5]*gtop_m[5])")
tree->SetAlias("Pzt1","gtop_pt[2]*sinh(gtop_eta[2])")
tree->SetAlias("Pzt2","gtop_pt[5]*sinh(gtop_eta[5])")
tree->Draw("sqrt(gtop_m[2]*gtop_m[2]+gtop_m[5]*gtop_m[5]+2*(Et1*Et2-gtop_pt[2]*gtop_pt[5]*cos(gtop_phi[2]-gtop_phi[5]) - Pzt1*Pzt2))")
//OR
tree->Draw("sqrt(gtop_m[2]*gtop_m[2]+gtop_m[5]*gtop_m[5]+2*(sqrt(gtop_pt[2]*gtop_pt[2]*cosh(gtop_eta[2])*cosh(gtop_eta[2])+gtop_m[2]*gtop_m[2])*sqrt(gtop_pt[5]*gtop_pt[5]*cosh(gtop_eta[5])*cosh(gtop_eta[5])+gtop_m[5]*gtop_m[5]) - gtop_pt[2]*gtop_pt[5]*cos(gtop_phi[2]-gtop_phi[5])) - gtop_pt[2]*gtop_pt[5]*(cosh(gtop_eta[2]+gtop_eta[5])-cosh(gtop_eta[2]-gtop_eta[5])))")

Making flat ntuples

To process the ntuples (nanoAODs) execute the following:

ln -s /eos/cms/store/cmst3/group/top/exclusive_top/excl_ttbar_QED/NanoAOD/excl_ttbar_WmLep_QED.root MiniEvents.root
python $CMSSW_BASE/src/TopLJets2015/TopAnalysis/scripts/runLocalAnalysis.py -i MiniEvents.root -o ntuple.root --njobs 1 -q local --era era2017 -m RunExclusiveTop2020 --skimtree True

PPS reconstruction (data)

Submit to grid

After the local tests are successful, one can process all the data on the grid. Run the following code:

python $CMSSW_BASE/src/TopLJets2015/TopAnalysis/scripts/submitToGrid.py --lfn /store/group/cmst3/user/mpitt/ttbar -j samples.json -c ${CMSSW_BASE}/src/TopLJets2015/TopAnalysis/test/runMiniAnalyzer_cfg.py --only MC --workDir grid --xangle=120

samples.json is a file that contains list of MC samples to be submitted to the grid, for example:

{
"MC13TeV_2017_TTJets_v1"                : [832, 0,     "/TTJets_TuneCP5_13TeV-amcatnloFXFX-pythia8/RunIISummer19UL17MiniAOD-106X_mc2017_realistic_v6-v2/MINIAODSIM", "t#bar{t}", 920, true, false, 1]
}

• Inspect the submission process proceeds: crab status -d grid/crab_MC13TeV_2017_TTJets_v1
  • In case of errors, use crab status --verboseErrors for details
  • To resubmit failed jobs with extra options: crab resubmit -d grid/crab_MC13TeV_2017_TTJets_v1 --maxmemory=4000 --maxjobruntime=360 --numcores=1
  • To kill the current job: crab kill -d grid/crab_MC13TeV_2017_TTJets_v1
• The results will appear in cat grid/MC13TeV_2017_TTJets_v1_cfg.py | grep config.Data.outLFNDirBase | awk '{print $3}' | sed -e 's/"\//\/eos\/cms\//g' | sed -e 's/\/group//g' | sed -e 's/"//g'

Analysis

Plots

execute this and that

Inference

execute this and that

-- MichaelPitt - 2019-12-07

• ProtonReco.zip: cfg file for FastSim of tagged protons

• GEN_10_6_15_ProtonReco.tar.gz: production of exclusive ttbar events with CMS