Radiative Scaling Neutrino Mass with $A_4$ Symmetry

TL;DR

This paper explores a novel one-loop neutrino mass generation mechanism involving dark matter and $A_4$ symmetry, providing an alternative to the seesaw model with specific phenomenological implications.

Contribution

It introduces an $A_4$ symmetric implementation of a radiative neutrino mass model with keV-scale Majorana fermions and discusses its phenomenology.

Findings

Neutrino masses are generated via a one-loop process involving dark matter.

The model predicts specific signatures for the $N_i$ fermions and scalar doublet.

Implementation with $A_4$ symmetry explains neutrino mixing patterns.

Abstract

A new idea for neutrino mass was proposed recently, where its smallness is not due to the seesaw mechanism, i.e. not inversely proportional to some large mass scale. It comes from a one-loop mechanism with dark matter in the loop consisting of singlet Majorana fermions $N_i$ with masses of order 10 keV and neutrino masses are scaled down from them by factors of about $10^{-5}$. We discuss how this model may be implemented with the non-Abelian discrete symmetry $A_4$ for neutrino mixing, and consider the phenomenology of $N_i$ as well as the extra scalar doublet $(\eta^+,\eta^0)$.