Lepton Flavor Violation in the singlet-triplet scotogenic model

TL;DR

This paper analyzes lepton flavor violation in a singlet-triplet scotogenic model, highlighting its unique dark matter features and identifying promising experimental signals like LFV 3-body decays and mu-e conversion.

Contribution

It introduces a variant of the scotogenic model with triplet fermions and scalars, expanding the dark matter and LFV phenomenology beyond the standard model.

Findings

LFV 3-body decays are promising experimental signals.

Coherent mu-e conversion in nuclei is highly constraining.

The model's parameter space aligns with current neutrino oscillation data.

Abstract

We investigate lepton flavor violation (LFV) in the the singlet-triplet scotogenic model in which neutrinos acquire non-zero masses at the 1-loop level. In contrast to the most popular variant of this setup, the singlet scotogenic model, this version includes a triplet fermion as well as a triplet scalar, leading to a scenario with a richer dark matter phenomenology. Taking into account results from neutrino oscillation experiments, we explore some aspects of the LFV phenomenology of the model. In particular, we study the relative weight of the dipole operators with respect to other contributions to the LFV amplitudes and determine the most constraining observables. We show that in large portions of the parameter space, the most promising experimental perspectives are found for LFV 3-body decays and for coherent $\mu-e$ conversion in nuclei.