Phenomenological constraints on minimally coupled exotic lepton triplets

Abstract

By introducing a set of new triplet leptons (with nonzero hypercharge) that can Yukawa couple to their standard model counterparts, new sources of tree-level flavor changing currents are induced via mixing. In this work, we study some of the consequences of such new contributions on processes such as the leptonic decays of gauge bosons, $\ensuremath{\ell}\ensuremath{\rightarrow}3{\ensuremath{\ell}}^{\ensuremath{'}}$ and $\ensuremath{\ell}\ensuremath{\rightarrow}{\ensuremath{\ell}}^{\ensuremath{'}}\ensuremath{\gamma}$, which violate lepton flavor, and $\ensuremath{\mu}\ensuremath{-}e$ conversion in atomic nuclei. Constraints are then placed on the parameters associated with the exotic triplets by invoking the current low-energy experimental data. Moreover, the new physics contribution to the lepton anomalous magnetic moments is calculated.