Exercise 6: Muon Tracking Efficiency using T&P method

The Tag and Probe tool is a generic tool developed to measure any user defined object efficiency from data at CMS by exploiting di-object resonances like Z or J/Psi. the efficiency is measured as following:

• Resonances are reconstructed as pairs with one leg passing a tight selection which called (tag) and the other one passing a loose selection (probe).
• Passing probes are defined according to whatever is the efficiency to measure.
• the (tag + passing probe) and (tag + failing probe) lineshapes are fit separately with a signal + background model.
• then the efficiency is computed from the ratio of the passing probe and all probe.
• the procedures can be done for any probe variable (e.g. p_T, η ...) to compute efficiency histograms as a function of those variables.

Step 1: Create and set up a CMSSW working area

set up the release:

cmsrel CMSSW_9_4_0_pre3
cd CMSSW_9_4_0_pre3/src
cmsenv

get core packages:

git cms-merge-topic HuguesBrun:updateL3MuonCollectionsToMatch 
git clone git@github.com:GLP90/Tnp94.git MuonAnalysis/TagAndProbe -b 94_newSelector 
git cms-addpkg PhysicsTools/PatAlgos

compile the package

cmsenv
 scramv1 b -j 5

To produce the Ntuples, put bool simInfoIsAvailalbe=false in link

cmsenv
git cms-addpkg PhysicsTools/PatAlgos
vim PhysicsTools/PatAlgos/plugins/PATMuonProducer.cc 
(modify the line mentioned above)

For adding the standalone muon to the tree, replace the files in your the folder of your local working area by those ones

xrdcp -f root://cmseos.fnal.gov///store/user/cmsdas/2018/short_exercises/Muons/Exercises/MuonExercise6/tp_from_aod_Data.py MuonAnalysis/TagAndProbe/test/zmumu/tp_from_aod_Data.py
xrdcp -f root://cmseos.fnal.gov///store/user/cmsdas/2018/short_exercises/Muons/Exercises/MuonExercise6/tp_from_aod_MC.py MuonAnalysis/TagAndProbe/test/zmumu/tp_from_aod_MC.py

Step 2: Skim the T&P trees

With the program skimTree, you can reduce 'T&P ntuples' size by applying cuts on a specified input tree and copy the result to an output ROOT file. Moreover, you can remove branches from the tree completely. This is mainly done to reduce the file size and therefore to reduce the memory consumption and processing time for T&P studies. Note, that you can load multiple files at once from your local storage device or EOS and merge them together in the output.

The tool can be found as part of the cms-MuonPOG/TnPUtils package

git clone https://github.com/cms-MuonPOG/TnPUtils.git

Then copy the template file "skimTree" to the folder of your local working area

xrdcp -f root://cmseos.fnal.gov///store/user/cmsdas/2018/short_exercises/Muons/Exercises/MuonExercise6/skimTree TnPUtils/skimTree

Both data and MC have been skimmed using

./skimTree root://cmseos.fnal.gov///store/user/cmsdas/2018/short_exercises/Muons/Exercises/MuonExercise6/TnPTree_17Nov2017_SingleMuon_Run2017Bv1_Full_GoldenJSON.root TnPTree_17Nov2017_SingleMuon_Run2017Bv1_Full_GoldenJSON.root -r "all" -k "mass pt eta abseta phi staValidStations staQoverPerror tk_deltaR tk_deltaEta tk_deltaR_NoZ tk_deltaEta_NoZ tk0_deltaR tk0_deltaEta tk0_deltaR_NoZ tk0_deltaEta_NoZ tag_nVertices tag_vz tag_bx tag_combRelIsoPF04dBeta run lumi tag_instLumi tag_eta tag_IsoMu24_eta2p1 outerValidHits StaTkSameCharge" -c "(tag_combRelIsoPF04dBeta < 0.15 && tag_combRelIsoPF04dBeta > -0.5 && mass > 69.5 && mass < 130.1 && tag_pt > 23 && (tag_IsoMu22 == 1|| tag_IsoMu24 == 1) && abseta <2.401)"

./skimTree root://cmseos.fnal.gov///store/user/cmsdas/2018/short_exercises/Muons/Exercises/MuonExercise6/DYJetsToLL_M-50_TuneCP5_13TeV-madgraphMLM-pythia8.root DYJetsToLL_M-50_TuneCP5_13TeV-madgraphMLM-pythia8.root -r "all" -k "mass pt eta abseta phi staValidStations staQoverPerror tk_deltaR tk_deltaEta tk_deltaR_NoZ tk_deltaEta_NoZ tk0_deltaR tk0_deltaEta tk0_deltaR_NoZ tk0_deltaEta_NoZ tag_nVertices tag_vz tag_bx tag_combRelIsoPF04dBeta run lumi tag_instLumi tag_eta tag_IsoMu24_eta2p1 outerValidHits StaTkSameCharge mcTrue weight" -c "(tag_combRelIsoPF04dBeta < 0.15 && tag_combRelIsoPF04dBeta > -0.5 && mass > 69.5 && mass < 130.1 && tag_pt > 23 && (tag_IsoMu22 == 1|| tag_IsoMu24 == 1) && abseta <2.401)"

Step 3: Running the fits on your data and MC files

The configuration file used to perform the fit is MuonAnalysis /TagAndProbe/test/zmumu/fitTracking.py

Copy the python file to the folder of your local working area:

xrdcp -f root://cmseos.fnal.gov///store/user/cmsdas/2018/short_exercises/Muons/Exercises/MuonExercise6/fitTracking.py MuonAnalysis/TagAndProbe/test/zmumu/fitTracking.py

The module takes as input

• A set of skimmed rootfiles produced from step 2
• Information about which columns to use inside of the dataset:
  • for the binning variables for the efficiency (e.g. p_T, η, φ)).
  • select which type of files you will run on (Data or MC).
• A lineshape model, parametrized using RooFit classes

• Signal: sum of 2 Voigtians.
• Background: Exponential.

PDFs = cms.PSet(
vpvPlusExpo = cms.vstring(
"Voigtian::signal1(mass, mean1[90,80,100], width[2.495], sigma1[2,1,3])",
"Voigtian::signal2(mass, mean2[90,80,100], width, sigma2[4,2,10])",
"SUM::signal(vFrac[0.8,0,1]*signal1, signal2)",
"Exponential::backgroundPass(mass, lp[-0.1,-1,0.1])",
"Exponential::backgroundFail(mass, lf[-0.1,-1,0.1])",
"efficiency[0.9,0,1]",
"signalFractionInPassing[0.9]"
),
),

Open your python file and modify it by putting your files which you got in step 2 as input files "Line 215":

if "TestData_" in scenario:
process.TnP_Tracking.InputFileNames = ["TnPTree_17Nov2017_SingleMuon_Run2017Bv1_Full_GoldenJSON.root"]
if "TestMC_" in scenario:
process.TnP_Tracking.InputFileNames = [ "DYJetsToLL_M-50_TuneCP5_13TeV-madgraphMLM-pythia8.root"]

To produce the fit files for data using eta binning you can use

cmsRun MuonAnalysis/TagAndProbe/test/zmumu/fitTracking.py TestData_et3

And to produce the fit files for MC using eta binning you can use

cmsRun MuonAnalysis/TagAndProbe/test/zmumu/fitTracking.py TestMC_et3

Step 4: Calculate the muon tracking efficiency

Between RunI and RunII, some developments have been made in the CMS experiment in different aspects of the tracking procedure in order to cope with the increasing luminosity.

There are two new iterations dedicated exclusively to muons.

• An outside-in track reconstruction step seeded in the muon system.
• An inside-out iteration that re-reconstructs muon-tagged tracks.

Copy these two C++ files to the folder of your local working area:

xrdcp -f root://cmseos.fnal.gov///store/user/cmsdas/2018/short_exercises/Muons/Exercises/MuonExercise6/plotTracking.cxx MuonAnalysis/TagAndProbe/test/zmumu/plotTracking.cxx
xrdcp -f root://cmseos.fnal.gov///store/user/cmsdas/2018/short_exercises/Muons/Exercises/MuonExercise6/plotUtil_Tracking.cxx    MuonAnalysis/TagAndProbe/test/zmumu/plotUtil_Tracking.cxx

For producing the tracking efficiency for the All- tracks collection as a function of pseudorapidity " η".

root -b -l -q TnP_Tracking_dr030e030_TestData_et3.root TnP_Tracking_dr030e030NoZ_TestData_et3.root TnP_Tracking_dr030e030_TestMC_et3.root TnP_Tracking_dr030e030NoZ_TestMC_et3.root MuonAnalysis/TagAndProbe/test/zmumu/plotTracking.cxx

Then to produce the tracking efficiency for the Tracker only seeded tracks collection as a function of pseudorapidity "η".

root -b -l -q TnP_Tracking_tk0_dr030e030_TestData_et3.root TnP_Tracking_tk0_dr030e030NoZ_TestData_et3.root TnP_Tracking_tk0_dr030e030_TestMC_et3.root TnP_Tracking_tk0_dr030e030NoZ_TestMC_et3.root MuonAnalysis/TagAndProbe/test/zmumu/plotTracking.cxx