Compositeness Effects in the Anomalous Weak-Magnetic Moment of Leptons

Abstract

We investigate the effects induced by excited leptons, at the one-loop level, in the anomalous magnetic and weak-magnetic form factors of the leptons. Using a general effective Lagrangian approach to describe the couplings of the excited leptons, we compute their contributions to the weak-magnetic moment of the $\tau$ lepton, which can be measured on the $Z$ peak, and we compare it with the contributions to $g_\mu - 2$, measured at low energies.