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Measurement of the top quark pair production cross section in dilepton final states containing one $τ$ lepton in pp collisions at $\sqrt{s} =$ 13 TeV

Journal Contribution - Journal Article

The cross section of top quark pair production is measured in the $\mathrm{t\bar{t}}$ $\to$ $(\ell\nu_{\ell})(\tau_\mathrm{h}\nu_{\tau})\mathrm{b\bar{b}}$ final state, where $\tau_\mathrm{h}$ refers to the hadronic decays of the $\tau$ lepton, and $\ell$ is either an electron or a muon. The data sample corresponds to an integrated luminosity of 35.9 fb$^{-1}$ collected in proton-proton collisions at $\sqrt{s} =$ 13 TeV with the CMS detector. The measured cross section is $\sigma_{\mathrm{t\bar{t}}} =$ 781 $\pm$ 7 (stat) $\pm$ 62 (syst) $\pm$ 20 (lum) pb, and the ratio of the partial width $\Gamma($t $\to$ $\tau\nu_{\tau}$b) to the total decay width of the top quark is measured to be 0.1050 $\pm$ 0.0009 (stat) $\pm$ 0.0071 (syst). This is the first measurement of the $\mathrm{t\bar{t}}$ production cross section in proton-proton collisions at $\sqrt{s} =$ 13 TeV that explicitly includes $\tau$ leptons. The ratio of the cross sections in the $\ell\tau_\mathrm{h}$ and $\ell\ell$ final states yields a value $R_{\ell\tau_\mathrm{h}/\ell\ell} =$ 0.973 $\pm$ 0.009 (stat) $\pm$ 0.066 (syst), consistent with lepton universality.
Journal: Journal of High Energy Physics
ISSN: 1126-6708
Issue: 02
Volume: 2020
Number of pages: 41
Publication year:2020
  • Scopus Id: 85080991624
  • ORCID: /0000-0002-7366-7098/work/75206564
  • ORCID: /0000-0002-9598-6241/work/75206781
  • ORCID: /0000-0002-8564-8732/work/75207104
  • DOI: https://doi.org/10.1007/jhep02(2020)191
  • ORCID: /0000-0002-6792-9522/work/79142212
  • ArticleNumber: 191