Two-lepton/four-lepton analysis example of CMS 2010 open data
Rodriguez Marrero, Ana
Cite as: Rodriguez Marrero, Ana; (2014). Two-lepton/four-lepton analysis example of CMS 2010 open data. CERN Open Data Portal. DOI:10.7483/OPENDATA.CMS.QXY9.X47P
Data recorded in 2010 and published in 2014Software Analysis CMS CERN-LHC
Description
Example code for a simple analysis on Z decays to two leptons and ZZ decays to four leptons. Please see below the details on data selection and the generated example plots.
Running the analysis code on the pre-processed datasets takes several hours.
Use with
Use this with the following datasets:
Characteristics
1 file. 20.6 KiB in total.System details
Use this code with the CMS Open Data VM environmentCMSSW_4_2_8
Data selection
An event selection is applied in the two analysis cases:
- In the Z analysis at least two leptons with opposite charge, with invariant mass ”mll” between 12 GeV and 120 GeV are required. The pair with the invariant mass closest to the Z boson mass is selected as the Z candidate.
- In the ZZ analysis two Z candidates are required, and for both candidates, two leptons with opposite charge are required. The first Z candidate is required to have higher lepton momentum: 20 GeV for the first lepton and 10 GeV for the second lepton. The invariant mass is required to be in the range 40 GeV to 120 GeV. The second candidate is required to have an invariant mass higher then 4 GeV. The first candidate is the one with the invariant mass closest to the Z boson mass.
Selection criteria for electron candidates:
- pT > 7 GeV and |η| < 2.5;
- Distance between the electron z-vertex and the interaction z-vertex < 0.2 cm;
- Transverse impact parameter w.r.t. the beam spot < 0.04 cm;
- Symmetrised impact parameter w.r.t. the beam sport < 4 cm;
- Photon conversion rejection: number of lost hits in the tracker < 1;
- Electron identification: eIDLoose;
- Electron Isolation depends on the η region, regions with 1.44 < η 0.09; electron.dr03EcalRecHitSumEt()/electron.pt() > 0.07; and electron.dr03HcalTowerSumEt()/electron.pt() > 0.10. If η > 1.57: electron.dr03TkSumPt()/electron.pt() > 0.04; electron.dr03EcalRecHitSumEt()/electron.pt() > 0.05; and electron.dr03HcalTowerSumEt()/electron.pt() > 0.025. Each component is computed from Isodeposits in a cone of 0.3 around the electron direction.
Selection criteria for muon candidates:
- pT > 5 GeV and |η| < 2.4;
- Distance between the muon z-vertex and the interaction z-vertex < 0.2 cm;
- Is a GlobalMuon and TrackerMuon;
- Number of valid hits in the inner tracker > 10;
- χ2 /ndo f < 10 for the global muon fit;
- Transverse impact parameter w.r.t. the beam spot < 0.02 cm;
- Symmetrised impact parameter w.r.t. the beam sport < 4 cm;
- Relative Muon Isolation (RMI) < 0.15, with RMI = (ChargedHadronIso + NeutralHadronIso + PhotonIso)/pT(µ)
Each component is computed from Isodeposits in a cone of 0.3 around the muon direction.
Validation
The input files contain only the validated runs. For user validation of the analysis step, compare the result to the expected output file.
CMS list of validated runs Cert_136033-149442_7TeV_Apr21ReReco_Collisions10_JSON_v2.txt
Source code repository
https://github.com/ayrodrig/OutreachExercise2010Files and indexes
Disclaimer
These open data are released under the GNU General Public License v3.0.
Neither the experiment(s) ( CMS ) nor CERN endorse any works, scientific or otherwise, produced using these data.
This release has a unique DOI that you are requested to cite in any applications or publications.
