Effective Theory Approach to W-Pair Production near Threshold

Abstract

In this talk, I review the effective theory approach to unstable particle production and present results of a calculation of the process e- e+ ->mu- nubar_mu u dbar X near the W-pair production threshold up to next-to-leading order in GammaW/MW ~ alpha ~ v^2. The remaining theoretical uncertainty and the impact on the measurement of the W mass is discussed.

Comments: 7 pages (ilcws07.cls included), to appear in the proceedings of the International Linear Collider Workshop (LCWS/ILC07), 30 May - 3 Jun 2007, Hamburg, Germany