Measurements of inclusiveWandZcross sections in pp̄ collisions at √s = 1.96\, {{ TeV}}

We report the first measurements of inclusive W and Z boson cross-sections times the corresponding leptonic branching ratios for collisions at TeV based on the decays of the W and Z bosons into electrons and muons. The data were recorded with the CDF II detector at the Fermilab Tevatron and correspond to an integrated luminosity of 72.0 ± 4.3 pb −1 . We test e -μ lepton universality in W decays by measuring the ratio of the W → μν to W → e ν cross sections and determine a value of 0.991 ± 0.004(stat.) ± 0.011(syst.) for the ratio of W − ℓ − ν couplings ( g μ / g e ). Since there is no sign of non-universality, we combine our cross-section measurements in the different lepton decay modes and obtain nb and pb for dilepton pairs in the mass range between 66 GeV/ c 2 and 116 GeV/ c 2 . We compute the ratio R of the W → ℓν to Z → ℓℓ cross sections taking all correlations among channels into account and obtain R = 10.84 ± 0.15(stat.) ± 0.14(syst.) including a correction for the virtual photon exchange component in our measured γ*/ Z → ℓℓ cross section. Based on the measured value of R , we extract values for the W leptonic branching ratio, Br( W → ℓν)= 0.1082 ± 0.0022; the total width of the W boson, Γ( W )= 2092 ± 42 MeV; and the ratio of W and Z boson total widths, Γ( W )/Γ( Z )= 0.838 ± 0.017. In addition, we use our extracted value of Γ( W ) whose value depends on various electroweak parameters and certain CKM matrix elements to constrain the V cs CKM matrix element, | V cs | = 0.976 ± 0.030.