Inclusive top-antitop pair production cross section at 5.02 TeV with CMS

TL;DR

This paper reports a measurement of the top-antitop quark pair production cross section at 5.02 TeV using CMS data, combining results from different channels to achieve a precise value consistent with the Standard Model.

Contribution

First measurement of top-antitop production cross section at 5.02 TeV with combined analysis to improve precision.

Findings

Measured cross section: 62.6 pb with 7.9% total uncertainty.

Results agree with Standard Model predictions.

Combined analysis reduces statistical uncertainty.

Abstract

The top quark pair production cross section is measured in proton-proton collisions at a center-of-mass energy of 5.02 TeV. The data collected in 2017 by the CMS experiment at the LHC corresponding to an integrated luminosity of 304 pb$^{-1}$ are analyzed. The measurement is performed using events with one electron and one muon of opposite sign, and at least two jets. The measured cross section is found to be $\sigma_{\mathrm{t}\bar{\mathrm{t}}}~=~60.3~\pm5.0~\mathrm{(stat)}\pm2.8~\mathrm{(syst)}\pm0.9~\mathrm{(lumi)}$ pb. To reduce the statistical uncertainty, a combination with the result in the $\ell$+jets channel, based on 27.4 pb$^{-1}$ of data collected in 2015 at the same center-of-mass energy of 5.02 TeV, is then performed, obtaining a value of $\sigma_{\mathrm{t}\bar{\mathrm{t}}}~=~62.6~\pm4.1~\mathrm{(stat)}\pm3.0~\mathrm{(syst+lumi)}$ pb, with a total uncertainty of 7.9%, in agreement with the standard model.