Radiative decays of charged leptons in arbitrary order

Abstract

In radiative decays of charged leptons induced by non-degenerate neutrino masses and consequent lepton flavour-mixing, the dominant suppression factor at the 1-loop level is (Σ m_a² )/m_W², m_a being the mass of the ath neutrino. We show that this suppression factor is present in all orders in a class of models including the standard model.