Topics in electroweak physics

by Alberto SIRLIN (New York University)

Friday 28 Sept 2001, 14:00 → 15:00 Europe/Zurich

TH Auditorium (CERN)

i) The concepts of mass, width and partial widths of unstable particles are discussed in the context of gauge theories. The emphasis is on the issue of gauge dependence. The problems and proposed solutions are illustrated on the basis of the Nielsen Identities that describe the gauge dependence of Green functions. ii) Two basic radiative corrections of the Electroweak Theory, Dr and (Dr)_eff, are discussed in the SM and in the Higgsless scenario. In particular, (Dr)_eff is shown to be very sensitive to Electroweak Bosonic Corrections. iii) The recently-proposed 'Effective Scheme' to renormalize the Electroweak Sector of the SM is discussed. It shares the good convergence properties of the ar{MS} scheme but, at the same time, eliminates the scale ambiguity in finite orders of perturbation theory.