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

We have determined ${\mathit{m}}_{\mathit{W}}$=79.91\ifmmode\pm\else\textpm\fi{}0.39 GeV/${\mathit{c}}^{2}$ from an analysis of W\ensuremath{\rightarrow}e\ensuremath{\nu} and W\ensuremath{\rightarrow}\ensuremath{\mu}\ensuremath{\nu} data from the Collider Detector at Fermilab in p\ifmmode\bar\else\textasciimacron\fi{}p collisions at a c.m. energy of \ensuremath{\surd}s =1.8 TeV. This result, together with the world-average Z mass, determines the weak mixing angle to be ${\mathrm{sin}}^{2}$${\mathrm{\ensuremath{\theta}}}_{\mathit{W}}$=0.232\ifmmode\pm\else\textpm\fi{}0.008. Bounds on the top-quark mass are discussed.