Additional correction one needs to apply to MET for the 2017 (only 2017) dataset due to the ECAL endcap noise:
https://twiki.cern.ch/twiki/bin/view/CMS/ExoPreapprovalChecklist
Basically the whole point is to not include jets with 2.65<|eta|<3.139, and 15GeV <pt (raw) <50 GeV in the MET calculation. Practically speaking we just need to vectorially add back these jets in each event to the MET vector. Notice the pT of the jet to be used is the raw pT (before jet energy corrections). The name of the variable in the ntuples is ptRaw.
Email from @arapyan,
Additional correction one needs to apply to MET for the 2017 (only 2017) dataset due to the ECAL endcap noise:
https://twiki.cern.ch/twiki/bin/view/CMS/ExoPreapprovalChecklist
Basically the whole point is to not include jets with 2.65<|eta|<3.139, and 15GeV <pt (raw) <50 GeV in the MET calculation. Practically speaking we just need to vectorially add back these jets in each event to the MET vector. Notice the pT of the jet to be used is the raw pT (before jet energy corrections). The name of the variable in the ntuples is ptRaw.