CMS-TOP-21-008
Measurement of the top quark pole mass using tt+jet events in the dilepton final state in proton-proton collisions at √s = 13 TeV
A measurement of the top quark pole mass mtpole in events where a top quark-antiquark pair (tt) is produced in association with at least one additional jet (tt+jet) is presented. This analysis is performed using proton-proton collision data at √s = 13 TeV collected by the CMS experiment at the CERN LHC, corresponding to a total integrated luminosity of 36.3 fb−1. Events with two opposite-sign leptons in the final state (ee, μμ, eμ) are analyzed. The reconstruction of the main observable and the event classification are optimized using multivariate analysis techniques based on machine learning. The production cross section is measured as a function of the inverse of the invariant mass of the tt+jet system at the parton level using a maximum likelihood unfolding. Given a reference parton distribution function (PDF), the top quark pole mass is extracted using the theoretical predictions at next-to-leading order. For the ABMP16NLO PDF, this results in mtpole = 172.94 ± 1.37 GeV.