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

D\O{} has measured the inclusive production cross section of W and Z bosons in a sample of 13 ${\mathrm{pb}}^{\ensuremath{-}1}$ of data collected at the Fermilab Tevatron. The cross sections, multiplied by their leptonic branching fractions, for production in $p\overline{p}$ collisions at $\sqrt{s}=1.8$ TeV are ${\ensuremath{\sigma}}_{W}\mathrm{B}(\stackrel{\ensuremath{\rightarrow}}{W}e\ensuremath{\nu})=2.36\ifmmode\pm\else\textpm\fi{}0.02\ifmmode\pm\else\textpm\fi{}0.08\ifmmode\pm\else\textpm\fi{}0.13\mathrm{}\mathrm{nb},$ ${\ensuremath{\sigma}}_{W}\mathrm{B}(\stackrel{\ensuremath{\rightarrow}}{W}\ensuremath{\mu}\ensuremath{\nu})=2.09\ifmmode\pm\else\textpm\fi{}0.06\ifmmode\pm\else\textpm\fi{}0.22\ifmmode\pm\else\textpm\fi{}0.11\mathrm{}\mathrm{nb},$ ${\ensuremath{\sigma}}_{Z}\mathrm{B}(\stackrel{\ensuremath{\rightarrow}}{Z}{e}^{+}{e}^{\ensuremath{-}})=0.218\ifmmode\pm\else\textpm\fi{}0.008\ifmmode\pm\else\textpm\fi{}0.008\ifmmode\pm\else\textpm\fi{}0.012\mathrm{}\mathrm{nb}$, and ${\ensuremath{\sigma}}_{Z}\mathrm{B}(\stackrel{\ensuremath{\rightarrow}}{Z}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}})=0.178\ifmmode\pm\else\textpm\fi{}0.022\ifmmode\pm\else\textpm\fi{}0.021\ifmmode\pm\else\textpm\fi{}0.009\mathrm{}\mathrm{nb}$, 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 ${\ensuremath{\sigma}}_{W}\mathrm{B}(\stackrel{\ensuremath{\rightarrow}}{W}l\ensuremath{\nu})/{\ensuremath{\sigma}}_{Z}\mathrm{B}(\stackrel{\ensuremath{\rightarrow}}{Z}{l}^{+}{l}^{\ensuremath{-}})=10.90\ifmmode\pm\else\textpm\fi{}0.52$. Assuming standard model couplings, we use this result to determine the width of the W boson, and obtain $\ensuremath{\Gamma}(W)=2.044\ifmmode\pm\else\textpm\fi{}0.097 \mathrm{GeV}$.