| This dissertation describes a direct measurement of the W boson total decay width, GammaW, using the DO detector at the Fermilab Tevatron Collider. The measurement uses an integrated luminosity of 177.3 pb-1 data, collected during the 2002--2003 run. The width is determined from the shape of the transverse mass distribution, MT, by fitting the data in the tail region 100 < MT < 200 GeV. The result is GammaW = 2.011 +/- 0.093 (stat) +/- 0.107 (syst) GeV. |
