Electroweak radiative corrections to resonant charged gauge boson production

The electroweak O(a) contribution to the resonant single W production in a general four-fermion process is discussed with particular emphasis on a gauge-invariant decomposition into a QED-like and weak part. The cross section in the vicinity of the resonance can be represented in terms of a convolution of a "hard" Breit-Wigner cross section, comprising the (m_t,M_H)-dependent weak one-loop corrections, with a universal radiator function. The numerical impact of the various contributions on the W line shape are discussed, together with the concepts of s-dependent and constant width approaches. Analytic formulas for the W decay width are also provided including the one-loop electroweak and QCD corrections.