Extraction of the width of the W boson from measurements of σ(pp̄→W+X)×B(W→eν) and σ(pp̄→Z+X)×B(Z→ee) and their ratio

We report on measurements on inclusive cross sections times branching fractions into electrons for W and Z bosons produced in pp collisions at √s=1.8TeV. From an integrated luminosity of 84.5 pb -1 recorded in 1994-1995 using the DO detector at the Fermilab Tevatron, we determine σ(pp→W+X)×B(W → eν)=2310±10(stat)±50(syst)±100(lum)pb and σ(pp→Z+X)×B(Z → ee)=221±3(stat)±4(syst)±10(lum)pb. From these, we derive σ(pp→W+X)×B(W → eν)/σ(pp→Z+X)×B(Z → ee)=10.43±0.15(stat)±0.20(syst)±0.10(NLO), B(W → eν)=0.1044±0.0015(stat)±0.0020(syst)±0.0017(theory)±0.0010(NLO), and Γ W =2.169±0.031(stat)±0.042(syst)±0.041(theory)±0.022(NLO)GeV. We use the latter to set a 95% confidence level upper limit on the partial decay width of the W boson into nonstandard model final states, Γ W inv , of 0.213 GeV. Combining these results with those from the 1992-1993 data gives σ(pp→W+X)×B(W → eν)/σ(pp→Z+X)×B(Z → ee)=10.51±0.25, Γ W =2.152±0.066GeV, and a 95% C.L. upper limit on Γ W inv of 0.191 GeV. Using a sample with a luminosity of 505 nb -1 taken at √s=630GeV, we measure σ(pp→W+X)×B(W → eν)=658±67pb.