Applications of effective Lagrangians to weak radiative decays

Abstract

Using the effective Lagrangian approach we study the weak radiative processes H-0 --> gamma gamma, mu --> e gamma, tau --> mu gamma, e gamma and b --> s gamma. We assume that the full theory is perturbatively renormalizable and that nonrenormalizable interactions respects the symmetry of the standard model. We consider only those contributions generated at lowest level in the perturbative full theory. We find that the effects due to new physics may enhance the H --> gamma gamma SM decay width and its production in gamma gamma colliders up to one order of magnitude. We also get bounds on the fermion-number-nonconserving decays nu(i) --> nu(j) gamma and t --> c gamma as well on the anomalous electromagnetic couplings of the W boson and the t, c, u quarks.