Radiative Corrections to W and Quark Propagators in the Resonance Region

Preprint
Publisher Website
Google Scholar
  • 17 April 1998
Abstract
We discuss radiative corrections to W and quark propagators in the resonance region, |s-M^2| \lsim M*Gamma. We show that conventional mass renormalization, when applied to photonic or gluonic corrections, leads in next to leading order (NLO) to contributions proportional to [M*Gamma/(s-M^2)]^n, (n=1,2...), i.e. to a non-convergent series in the resonance region. A solution of this difficulty, which affects all unstable particles coupled to massless quanta, is presented. It elucidates the issue of renormalization of amplitudes involving unstable particles, and automatically circumvents the problem of apparent on-shell singularities. The roles of the Fried-Yennie gauge and the Pinch Technique prescription are discussed. Because of special properties of the photonic and gluonic contributions, and in contrast with the Z case, the gauge dependence of the conventional on-shell definition of mass is unbounded in NLO. The evaluations of the width in the conventional and modified formulations are compared and shown to agree in NLO but not beyond.

This publication has 0 references indexed in Scilit: