Lepton Flavor Violation in the Scotogenic Model

Abstract

We investigate lepton flavor violation in the scotogenic model proposed by Ma in which neutrinos acquire non-zero masses at the 1-loop level. Although some works exist in this direction, they have mainly focused on the radiative decay ${\ell }_{\alpha }\to {\ell }_{\beta }\gamma$. Motivated by the promising new projects involving other low-energy processes, we derive complete analytical expressions for ${\ell }_{\alpha }\to 3{\ell }_{\beta }$ and $\mu -e$ conversion in nuclei, and numerically study their impact on the phenomenology. We will show that these processes can actually have rates larger than the one for ${\ell }_{\alpha }\to {\ell }_{\beta }\gamma$, thus providing more stringent constraints and better experimental perspectives.

Comments: 28 pages, 16 figures. v2: New references and improved discussion of the non-degenerate scenario. Version to appear in JHEP