Combination of CDF and DO results on W boson mass and width.

The results based on 1992–95 data (Run 1) from the CDF and D0 experiments on the measurements of the W boson mass and width are presented, along with the combined results. We report a Tevatron collider average MW=80.456±0.059 GeV. We also report the Tevatron collider average of the directly measured W boson width ΓW=2.115±0.105 GeV. We describe a new joint analysis of the direct W mass and width measurements. Assuming the validity of the standard model, we combine the directly measured W boson width with the width extracted from the ratio of W and Z boson leptonic partial cross sections. This combined result for the Tevatron is ΓW=2.135±0.050 GeV. Finally, we use the measurements of the direct total W width and the leptonic branching ratio to extract the leptonic partial width Γ(W→eν)=224±13 MeV