Measurement of W and Z boson production cross sections in pp̄ collisions at √s=1.8 TeV

DO has measured the inclusive production cross section of W and Z bosons in a sample of 13 pb -1 of data collected at the Fermilab Tevatron. The cross sections, multiplied by their leptonic branching fractions, for production in pp collisions at √s=1.8 TeV are σ W B(W → ev)=2.36±0.02±0.08±0.13 nb, σ W B(W → μν)=2.09±0.06±0.22±0.11 nb, σ Z B(Z → e + e - )=0.218±0.008±0.008±0.012 nb, and σ Z B(Z → μ + μ - )=0.178±0.022±0.021±0.009 nb, where the first uncertainty is statistical and the second systematic; the third reflects the uncertainty in the integrated luminosity. For the combined electron and muon analyses, we find σ W B(W → lν)/σ Z B(Z → l + l - )=10.90±0.52. Assuming standard model couplings, we use this result to determine the width of the W boson, and obtain Γ(W)=2.044±0.097 GeV.