Electron trigger efficiencies
EGM links:
- EGM HLT Path details
- CMS Talk mentions of EGM trigger efficiency
- Approved and ongoing electron and photon trigger scale factor measurements for Run2 data
- EgammaAnalysis-TnPTreeProducer Repository
- egm_tnp_analysis Repository
From this PubTalk thread: The HLT SFs for electrons are normally calculated using a Tag and Probe - you can use the code in [3], if you want. The idea is to select a pair of electrons that likely come from a known resonance (Z), apply tight identification cuts on one of them (tag) and use the other one (probe) to measure the efficiency for passing the desired HLT path. Note that the efficiency is in general different for electrons with different offline ID criteria, so one needs to apply the analysis’ offline cuts to the probe when measuring the efficiency and the scale factors. The EGM Tag and Probe tool that I’ve mentioned works on ntuples like those in these directories:
/eos/cms/store/group/phys_egamma/tnpTuples/tomc/2020-05-20/UL2018/merged (2018) /eos/cms/store/group/phys_egamma/tnpTuples/tomc/2020-05-20/UL2017/merged (2017) /eos/cms/store/group/phys_egamma/tnpTuples/rasharma/2021-02-10/UL2016postVFP/merged (2016 post-VFP) /eos/cms/store/group/phys_egamma/tnpTuples/rasharma/2021-02-10/UL2016preVFP/merged (2016 pre-VFP)
These ntuples were not made using the latest UL campaign, but we found the differences to be negligible. In the ntuples you will find a boolean that tells you, for instance, whether your probe has passed or not HLT_Ele32_WPTight_Gsf. This code allows you to apply to the probe electron the desired HLT filter and the same selection as you use offline, and also to include a few systematic uncertainties in your efficiency and SF measurements. There are basic instructions in the readme, but do not hesitate to ask should you have any doubt.
[1] https://twiki.cern.ch/twiki/bin/view/CMS/EgHLTRunIISummary#2017 [2] https://twiki.cern.ch/twiki/bin/view/CMS/EgammaNanoAOD#Trigger_bits_how_to [3] https://github.com/cms-egamma/egm_tnp_analysis 1 [4] https://twiki.cern.ch/twiki/bin/view/CMS/EgHLTScaleFactorMeasurements