L1 Analyzer

Complete: 4


The aim of the package is to provide tools to validate the L1 Emulator and study the performance of the L1 Trigger. This is accomplished by matching the L1 candidates to reference collections (either offline or MC truth) and then calculating resolutions, efficiencies etc.


The implementation is spilt into four stages.

  • Define the input collections and convert them into particle candidates. The conversion should become unnecessary when framework views are available in the candidate tools.

  • Make cuts on the input particle candidate collections.

  • Match the L1 to GEN or RECO particles.

  • Calculate efficiencies, resolutions etc.

Installing L1Analyzer

Setup a project area to work with CMSSW 1_7_X and check out the following tag:

cvs co -r V00-02-24 L1TriggerOffline/L1Analyzer

Running L1Analyzer

You can run the L1Analyzer by including one of the following in your cfg file.

include "L1TriggerOffline/L1Analyzer/data/L1NonIsoEmMCAnalysis.cff"
include "L1TriggerOffline/L1Analyzer/data/L1NonIsoEmRecoAnalysis.cff"
include "L1TriggerOffline/L1Analyzer/data/L1IsoEmMCAnalysis.cff"
include "L1TriggerOffline/L1Analyzer/data/L1IsoEmRecoAnalysis.cff"
include "L1TriggerOffline/L1Analyzer/data/L1CenJetMCAnalysis.cff"
include "L1TriggerOffline/L1Analyzer/data/L1CenJetRecoAnalysis.cff"
include "L1TriggerOffline/L1Analyzer/data/L1ForJetMCAnalysis.cff"
include "L1TriggerOffline/L1Analyzer/data/L1ForJetRecoAnalysis.cff"
include "L1TriggerOffline/L1Analyzer/data/L1MetMCAnalysis.cff"
include "L1TriggerOffline/L1Analyzer/data/L1MetRecoAnalysis.cff"
include "L1TriggerOffline/L1Analyzer/data/L1MuonMCAnalysis.cff"
include "L1TriggerOffline/L1Analyzer/data/L1MuonRecoAnalysis.cff"
include "L1TriggerOffline/L1Analyzer/data/L1TauJetMCAnalysis.cff"
include "L1TriggerOffline/L1Analyzer/data/L1TauJetRecoAnalysis.cff"

and including the sequence name (eg. L1NonIsoEmMCAnalysis) in your path. Note that you may also need to have run the L1Emulator, details here.


The output of the default configurations is a ROOT file named l1Analyzer.root. Inside the file is a main directory and inside that are four subdirectories containing simple kinematic distributions, efficiencies and resolutions. The screenshot shows the contents of the resolutions subdirectory for the L1 non-isolated EM match with MC truth.


The ROOT macro test/l1Analyzer.C can be used to plot histograms.

Changing parameters

There are many parameters that can be changed for different studies. A couple to get started with are:

  • Histogram binning and ranges in HistoLimits.cfi
  • The name of the output root file in TFile.cfi

In each of the above cff files there are many parameters to change. As an example take the L1NonIsoEmMCAnalysis.cff

  • Minimum Pt of the L1 non-isolated EM candidates (default 5 GeV)
  • Minimum Pt and eta range of the generator electrons (default 5 GeV and |eta|<3)
  • Maximum delta R for a L1 - generator candidate match (default 0.5)

Possible future plans

  • Add electron isolation
  • Add cff for photons
  • Add Ht and Total Et
  • More selectors? Leading jet? Two eta ranges for forward jet studies?
  • One to many matching?
  • Change MC truth tau to tau jet
  • Macro to merge histograms from different jobs
  • L1 trigger summary
  • Use framework views

Review Status

Editor/Review and date Comments
AlexTapper - 26 Nov 2007 Page Author

Responsible: AlexTapper
Last reviewed by:

Topic attachments
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