CMS Open Data - Compact Jet Tuples

In order to facilitate analysis, the CMS Jet 2011 data and Monte Carlo sets have been converted into a compact form, sometimes called flat tuple. This page aggregates information about the compactified files.

General description

Currently, two tuple files are needed in the analysis, and they are publicly available here: https://cernbox.cern.ch/index.php/s/1gGQi8FZPI1gHW2

• The experimental CMS jet data from 2011 (size: 7.7 GB):

   OpenDataTuple-Data-Jet-Run2011A.root 

  Converted from the AOD file: http://opendata.cern.ch/record/21
• The corresponding Monte Carlo simulation carried out in the Pythia 6 program (size: 2.3 GB):

  OpenDataTuple-MC-QCD_Pt-15to1000_TuneZ2_7TeV_pythia6.root 

Variable definitions

The files are TTree ROOT objects (https://root.cern.ch/doc/master/classTTree.html). Each event is saved into an entry of the TTree, which contains the variables listed below. The variables are either scalars (e.g. number of jets in the event) or vectors (e.g. transverse momentum pT of the jets in the event).

1. Properties of the event Show... Hide

1. Jets reconstructed using the anti-kT algorithm with a parameter R = 0.5 (abbr. AK5).
   Show... Hide
   • njet; // Number of AK5 jets
   • jet_pt[njet]; // Corrected transverse momentum
   • jet_eta[njet]; // Pseudorapidity
   • jet_phi[njet]; // Azimuthal angle
   • jet_E[njet]; // Energy
2. Other AK5 jet information
   Show... Hide
   • jet_tightID[njet]; // Tight selection pass/fail
   • jet_area[njet]; // Jet area in eta-phi plane
   • jet_jes[njet]; // Jet energy correction
   • jet_igen[njet]; // Index of the matching generated jet
3. Composition values of the AK5 jets
   Show... Hide
   • chf[njet]; // Charged hadron energy fraction
   • nhf[njet]; // Neutral hadron energy fraction
   • phf[njet]; // Photon energy fraction
   • elf[njet]; // Electron energy fraction
   • muf[njet]; // Muon energy fraction
   • hf_hf[njet]; // Forward calorimeter (HF) hadron energy fraction
   • hf_phf[njet]; // HF photon energy fraction
   • hf_hm[njet]; // HF hadron multiplicity
   • hf_phm[njet]; // HF photon multiplicity
   • chm[njet]; // Charged hadron multiplicity
   • nhm[njet]; // Neutral hadron multiplicity
   • phm[njet]; // Photon multiplicity
   • elm[njet]; // Electron multiplicity
   • mum[njet]; // Muon multiplicity
   • beta[njet]; // Fraction of chf associated to the hard process
   • bstar[njet]; // Fraction of chf associated to pile-up
4. Jets reconstructed using the anti-kT algorithm with a parameter R = 0.7 (short. AK7)
   Show... Hide
   • njet_ak7; // Number of jets
   • jet_pt_ak7[njet_ak7]; // Transverse momentum
   • jet_eta_ak7[njet_ak7]; // Pseudorapidity
   • jet_phi_ak7[njet_ak7]; // Azimuthal angle
   • jet_E_ak7[njet_ak7]; // Energy
   • jet_area_ak7[njet_ak7]; // Jet area
   • jet_jes_ak7[njet_ak7]; // Jet energy corection factor
   • ak7_to_ak5[njet_ak7]; // Index of the corresponding AK5 jet
5. Monte Carlo simulation variables (only MC datasets)
   Show... Hide
   • ngen; // Number of jets generated
   • gen_pt[ngen]; // Transverse momentum
   • gen_eta[ngen]; // Pseudorapidity
   • gen_phi[ngen]; // Azimuthal angle
   • gen_E[ngen]; // Energy
   • float pthat; // Transverse momentum in the rest frame of the hard interaction
   • float mcweight; // Monte Carlo weight of the event

-- MatiasJacquesHaapalehto - 2017-01-19