Measurement of the top quark mass with lepton+jets final states in pp collisions at $\sqrt{s}=13~\mathrm{TeV}$

TL;DR

This paper measures the top quark mass using lepton+jets events from proton-proton collisions at 13 TeV, employing a kinematic fit and jet energy scale calibration, achieving a precise result with systematic uncertainties considered.

Contribution

It introduces a measurement of the top quark mass at 13 TeV with a simultaneous fit for jet energy scale, calibrated with NLO simulations, improving precision over previous methods.

Findings

Top quark mass measured as 172.25 GeV with combined statistical and systematic uncertainties.

Calibration of the measurement using NLO matched simulations enhances accuracy.

Study of kinematic dependencies compared to different t-tbar production models.

Abstract

The mass of the top quark is measured using a sample of $\rm{t}\bar{\rm t}$ candidate events with one lepton, muon or electron, and at least four jets in the final state, collected by the CMS detector in pp collisions at $\sqrt{s}=13~\mathrm{TeV}$ at the CERN LHC. The candidate events are selected from data corresponding to an integrated luminosity of $35.9~\mathrm{fb}^{-1}$. For each event the mass is reconstructed from a kinematic fit of the decay products to a $\rm{t}\bar{\rm t}$ hypothesis. The top quark mass is determined simultaneously with an overall jet energy scale factor (JSF), constrained by the mass of the W boson in $\rm{q}\bar{\rm q}$ decays. The measurement is calibrated on samples simulated at next-to-leading order matched to parton shower. The top quark mass is found to be $172.25\pm 0.08\,\rm{(stat+JSF)} \pm 0.62\,\rm{(syst)}~\mathrm{GeV}$. The dependence of this result on event kinematical properties is studied and compared to predictions of different models of $\rm{t}\bar{\rm t}$ production.