Measurement of the<i>W</i>boson mass

We present a measurement of the W boson mass using data collected by the D0 experiment at the Fermilab Tevatron during 1994--1995. We identify W bosons by their decays to $e\ensuremath{\nu}$ final states. We extract the W mass ${M}_{W}$ by fitting the transverse mass and transverse electron momentum spectra from a sample of 28 323 $\stackrel{\ensuremath{\rightarrow}}{W}e\ensuremath{\nu}$ decay candidates. We use a sample of 3563 dielectron events, mostly due to $\stackrel{\ensuremath{\rightarrow}}{Z}\mathrm{ee}$ decays, to constrain our model of the detector response. From the transverse mass fit we measure ${M}_{W}=80.44\ifmmode\pm\else\textpm\fi{}0.10(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.07(\mathrm{syst})\mathrm{}$ GeV. Combining this with our previously published result from data taken in 1992--1993, we obtain ${M}_{W}=80.43\ifmmode\pm\else\textpm\fi{}0.11\mathrm{GeV}.$