Measurement of the mass and the width of the W boson at LEP

The mass and the total decay width of the W boson are measured with the L3 detector at the LEP e+e– collider using W-boson pairs produced in 0.7 fb–1 of data collected at centre-of-mass energies between 161 and 209 GeV. Combining semi-leptonic and fully-hadronic final states, the mass and the width of the W boson are determined to be \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \begin{array}{*{20}c} {m_{{\text{W}}} = 80.270}{ \pm 0.046}{ \pm 0.031\;{\text{GeV}}}{{\text{and}}} \\ {\Gamma _{{\text{W}}} = 2.18}{ \pm 0.11}{ \pm 0.09\;{\text{GeV}}}{} \\ \end{array} $$\end{document} where the first uncertainty is statistical and the second systematic.