Measurement of the cross section for t t ¯ production with additional jets and b jets in pp collisions at √s = 13 TeV


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Sirunyan A., Tumasyan A., Adam W., Ambrogi F., Bergauer T., Dragicevic M., ...More

Journal of High Energy Physics, vol.2020, no.7, 2020 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 2020 Issue: 7
  • Publication Date: 2020
  • Doi Number: 10.1007/jhep07(2020)125
  • Journal Name: Journal of High Energy Physics
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, INSPEC, zbMATH, Directory of Open Access Journals
  • Keywords: Hadron-Hadron scattering (experiments), Jets, Top physics
  • Yıldız Technical University Affiliated: No

Abstract

Measurements of the cross section for the production of top quark pairs in association with a pair of jets from bottom quarks (σtt ¯bb ¯) and in association with a pair of jets from quarks of any flavor or gluons (σtt ¯jj) and their ratio are presented. The data were collected in proton-proton collisions at a center-of-mass energy of 13 TeV by the CMS experiment at the LHC in 2016 and correspond to an integrated luminosity of 35.9 fb−1. The measurements are performed in a fiducial phase space and extrapolated to the full phase space, separately for the dilepton and lepton+jets channels, where lepton corresponds to either an electron or a muon. The results of the measurements in the fiducial phase space for the dilepton and lepton+jets channels, respectively, are σtt ¯jj = 2.36±0.02 (stat)±0.20 (syst) pb and 31.0±0.2 (stat)±2.9 (syst) pb, and for the cross section ratio 0.017 ± 0.001 (stat) ± 0.001 (syst) and 0.020 ± 0.001 (stat) ± 0.001 (syst). The values of σtt ¯bb ¯ are determined from the product of the σtt ¯jj and the cross section ratio, obtaining, respectively, 0.040±0.002 (stat)±0.005 (syst) pb and 0.62±0.03 (stat)±0.07 (syst) pb. These measurements are the most precise to date and are consistent, within the uncertainties, with the standard model expectations obtained using a matrix element calculation at next-to-leading order in quantum chromodynamics matched to a parton shower. [Figure not available: see fulltext.]