Pheno & Cosmo Implications of Scotogenic 3-loop Neutrino Mass Models

TL;DR

This paper explores three-loop radiative neutrino mass models that naturally explain small neutrino masses, align with dark matter observations, and have testable implications for lepton flavor violation and other phenomena.

Contribution

It introduces scotogenic-like models with three-loop neutrino mass generation, addressing naturalness and experimental constraints simultaneously.

Findings

Models fit neutrino oscillation data

Can explain dark matter relic abundance

Predict observable charged-lepton flavor violation

Abstract

Radiative seesaw models are examples of interesting and testable extensions of the Standard Model to explain the light neutrino masses. In radiative models at 1-loop level, such as the popular scotogenic model, in order to successfully reproduce neutrino masses and mixing, one has to rely either on unnaturally small Yukawa couplings or on a very small mass splitting between the CP-even and CP-odd components of the neutral scalar mediators. We discuss here scotogenic-like models where light-active neutrino masses arise at the three-loop level, providing a more natural explanation for their smallness. The proposed models are consistent with the neutrino oscillation data and allow to successfully accommodate the measured dark matter relic abundance. Depending on the specific realization, it is also possible to explain the W-mass anomaly and to generate the baryon asymmetry of the Universe via leptogenesis. The models lead to rich phenomenology, predicting sizable charged-lepton flavor violation rates, potentially observable in near future experiments, while satisfying all current constraints imposed by neutrinoless double-beta decay, charged-lepton flavor violation and electroweak precision observables.