Running of Radiative Neutrino Masses: The Scotogenic Model

TL;DR

This paper derives the complete renormalization group equations for the scotogenic model, revealing how neutrino parameter running differs from traditional models and enabling high-energy mixing patterns to produce realistic low-energy neutrino mixing.

Contribution

It provides the first full set of RGEs for the scotogenic model, illustrating structural properties and implications for neutrino mixing evolution.

Findings

RGEs reflect unique structural properties of the model

High-energy bimaximal mixing can lead to realistic low-energy patterns

Numerical example shows tendencies of neutrino parameter running

Abstract

We study the renormalization group equations of Ma's scotogenic model, which generates an active neutrino mass at 1-loop level. In addition to other benefits, the main advantage of the mechanism exploited in this model is to lead to a natural loop-suppression of the neutrino mass, and therefore to an explanation for its smallness. However, since the structure of the neutrino mass matrix is altered compared to the ordinary type I seesaw case, the corresponding running is altered as well. We have derived the full set of renormalization group equations for the scotogenic model which, to our knowledge, had not been presented previously in the literature. This set of equations reflects some interesting structural properties of the model, and it is an illustrative example for how the running of neutrino parameters in radiative models is modified compared to models with tree-level mass generation. We also study a simplified numerical example to illustrate some general tendencies of the running. Interestingly, the structure of the RGEs can be exploited such that a bimaximal leptonic mixing pattern at the high-energy scale is translated into a valid mixing pattern at low energies, featuring a large value of \theta_{13}. This suggests very interesting connections to flavour symmetries.