A Measurement of theWBoson Mass at the Fermilabpp¯Collider

We report a measurement of the W boson mass based on an integrated luminosity of $82{\mathrm{pb}}^{-1\mathrm{}}$ from $p\overline{p}$ collisions at $\sqrt{s}=1.8\mathrm{TeV}$ recorded in 1994–1995 by the D0 detector at the Fermilab Tevatron. We identify W bosons by their decays to $e\nu$ and extract the mass by fitting the transverse mass spectrum from 28 323 W boson candidates. A sample of 3563 dielectron events, mostly due to $Z\to \mathrm{ee}$ decays, constrains models of W boson production and the detector. We measure $M_W=80.44\mathrm{}\pm 0.10\left(\mathrm{stat}\right)\pm 0.07\left(\mathrm{syst}\right)\mathrm{GeV}$. By combining this measurement with our result form the 1992–1993 data set, we obtain $M_W=80.43\mathrm{}\pm 0.11\mathrm{GeV}$.