Measurement of the tt production cross-section and lepton differential distributions in e mu dilepton events from pp collisions at root s=13 TeV with the ATLAS detector


Aad G., Abbott B., Abbott D. C., Abud A. A., Abeling K., Abhayasinghe D. K., ...More

EUROPEAN PHYSICAL JOURNAL C, vol.80, no.6, 2020 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 80 Issue: 6
  • Publication Date: 2020
  • Doi Number: 10.1140/epjc/s10052-020-7907-9
  • Journal Name: EUROPEAN PHYSICAL JOURNAL C
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Communication Abstracts, INSPEC, zbMATH, Directory of Open Access Journals
  • Istanbul University Affiliated: Yes

Abstract

The inclusive top quark pair (tt) production cross-section sigma tt has been measured in proton-proton collisions at s=13TeV, using 36.1 fb-1 of data collected in 2015-2016 by the ATLAS experiment at the LHC. Using events with an opposite-charge e mu pair and b-tagged jets, the cross-section is measured to be: sigma tt=826.4 +/- 3.6(stat)+/- 11.5(syst)+/- 15.7(lumi)+/- 1.9(beam)pb,where the uncertainties reflect the limited size of the data sample, experimental and theoretical systematic effects, the integrated luminosity, and the LHC beam energy, giving a total uncertainty of 2.4%. The result is consistent with theoretical QCD calculations at next-to-next-to-leading order. It is used to determine the top quark pole mass via the dependence of the predicted cross-section on mtpole, giving mtpole=173.1-2.1+2.0GeV. It is also combined with measurements at s=7TeV and s=8TeV to derive ratios and double ratios of tt and Z cross-sections at different energies. The same event sample is used to measure absolute and normalised differential cross-sections as functions of single-lepton and dilepton kinematic variables, and the results are compared with predictions from various Monte Carlo event generators.