Combined Preliminary Results on the Mass and Width of the W Boson Measured by the LEP Experiment

The combinations of the preliminary W mass and width measurements of the LEP experiments are presented. Measurements of the W mass obtained from data corresponding to a total integrated luminosity of approximately 2500~\ipb\ are combined to give: \begin{eqnarray*} \Mw = 80.450\pm0.039~\GeVm. \end{eqnarray*} This result includes the LEP W mass determination from the threshold cross section measurement. The separate results from the $\WWqqln$ and $\WWqqqq$ decay channels are consistent, with a difference in the masses obtained from the two channels of \begin{eqnarray*} \Delta\Mw(\qqqq-\qqln) = +9\pm44~\MeVm. \end{eqnarray*} A direct measurement of the width of the W boson gives: \begin{eqnarray*} \Gw = 2.150\pm0.091~\GeVm. \end{eqnarray*} These results include all LEP published and preliminary measurements which were available in June 2001. \begin{center} \vskip 0.2cm \large\textbf{Prepared from contributions of the LEP collaborations \\ to the summer conferences 2001.}\\