Precision measurement of the W boson decay branching fractions in proton-proton collisions at s =13 TeV

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Tumasyan A., Adam W., Andrejkovic J., Bergauer T., Chatterjee S., Dragicevic M., ...More

Physical Review D, vol.105, no.7, 2022 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 105 Issue: 7
  • Publication Date: 2022
  • Doi Number: 10.1103/physrevd.105.072008
  • Journal Name: Physical Review D
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Chemical Abstracts Core, INSPEC, zbMATH
  • Hacettepe University Affiliated: Yes


© 2022 CERN.The leptonic and inclusive hadronic decay branching fractions of the W boson are measured using proton-proton collision data collected at s=13 TeV by the CMS experiment at the CERN LHC, corresponding to an integrated luminosity of 35.9 fb-1. Events characterized by the production of one or two W bosons are selected and categorized based on the multiplicity and flavor of reconstructed leptons, the number of jets, and the number of jets identified as originating from the hadronization of b quarks. A binned maximum likelihood estimate of the W boson branching fractions is performed simultaneously in each event category. The measured branching fractions of the W boson decaying into electron, muon, and tau lepton final states are (10.83±0.10)%, (10.94±0.08)%, and (10.77±0.21)%, respectively, consistent with lepton flavor universality for the weak interaction. The average leptonic and inclusive hadronic decay branching fractions are estimated to be (10.89±0.08)% and (67.32±0.23)%, respectively. Based on the hadronic branching fraction, three standard model quantities are subsequently derived: the sum of squared elements in the first two rows of the Cabibbo-Kobayashi-Maskawa (CKM) matrix ∑ij|Vij|2=1.984±0.021, the CKM element |Vcs|=0.967±0.011, and the strong coupling constant at the W boson mass scale, αS(mW2)=0.095±0.033.