Measurement of the top quark pole mass using $$ \textrm{t}\overline{\textrm{t}} $$+jet events in the dilepton final state in proton-proton collisions at $$ \sqrt{s} $$ = 13 TeV

Abstract

A measurement of the top quark pole mass $$ {m}_{\textrm{t}}^{\textrm{pole}} $$ m t pole in events where a top quark-antiquark pair ($$ \textrm{t}\overline{\textrm{t}} $$ t t ¯ ) is produced in association with at least one additional jet ($$ \textrm{t}\overline{\textrm{t}} $$ t t ¯ +jet) is presented. This analysis is performed using proton-proton collision data at $$ \sqrt{s} $$ 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 (e+e−, μ+μ−, e±μ∓) 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 $$ \textrm{t}\overline{\textrm{t}} $$ t t ¯ +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 $$ {m}_{\textrm{t}}^{\textrm{pole}} $$ m t pole = 172.93 ± 1.36 GeV.

Investigation of the scale dependence in the MSR and $$ \overline{\textrm{MS}} $$ top quark mass schemes for the $$ \textrm{t}\overline{\textrm{t}} $$ invariant mass differential cross section using LHC data

“…[20] by the CMS Collaboration which obtained m pole t = 170.5 ± 0.8 GeV based on the same NLO theory prediction. This result is systematically lower than other indirect pole mass measurements [21][22][23] and was reconfirmed by the subsequent analysis in ref. [24].…”

“…The result of ref. [20] is systematically lower than those obtained using inclusive tt cross section measurements [21][22][23]. The results of our analyses shown in eqs.…”

Precise determination of the top-quark on-shell mass via its scale- invariant perturbative relation to the top-quark mass *

“…Determining the top-quark mass accurately is helpful for testing the precision of the SM, assessing whether the vacuum is in stable or meta-stable state, and searching for new physics beyond the SM. Direct measurements of the top-quark mass exhibit high precision in proton-proton ( ) collisions at the LHC [1][2][3][4][5][6][7][8]; these measurements…”