TipsFor

Tips for TopTree analyses on 2012 8TeV data (CMSSW_53X)

This evolving page contains some tips for setting up an analysis of 2012 8TeV data based on TopTrees.

*WARNING* Do not attaempt to skim multiple DATA skims at once, this is fine for MC however.

*WARNING* Do not attempt to merge skimmed TopTrees with the root 'hadd' command. This will corrupt the trigger information in the TopTrees and lead to incorrect behaviour in your analysis.

Jet energy scale correction At production time, the latest JES correction is applied to the jets in the TopTrees via the GlobalTag. That means you usually do not need to apply JES corrections on the fly in your analysis. However, should more up-to-date corrections become available after your TopTrees have been produced, you can still apply these corrections on the fly.

Applying the JSON file in the skimmer For data TopTrees, the JSON file is now always applied in the skimmer. This option ensures only good lumi sections are includes in the skim and can not be changed by the user. When calculating the luminosity for a data TopTree, the user should ensure that the json file used is the same one as used in the skim.

Synchronisation exercise and selection class To maintain synchronisation with the reference selection of the CMS TOP PAG in 53X, some changes are being made in the commonly used Selection class. These changes will be as minor as possible and will be advertised here.

MET collection The name of of the MET collection in the TopTrees is now "PFMET_patType1CorrectedPFMetPF2PAT"