Radiative Transmission of Lepton Flavor Hierarchies

TL;DR

This paper presents a one-loop neutrino mass model within a left-right gauge framework, linking charged lepton masses to neutrino hierarchies, predicting large lepton mixing angles and a dark matter candidate.

Contribution

It introduces a novel one-loop neutrino mass model with reduced parameters, hierarchical right-handed neutrino masses, and natural large lepton mixing angles.

Findings

Predicts hierarchical right-handed neutrino masses from a $U(1)_H$ symmetry

Allows for large but not maximal lepton mixing angles

Includes a dark matter candidate in the form of an inert doublet scalar

Abstract

We discuss a one loop model for neutrino masses which leads to a seesaw-like formula with the difference that the charged lepton masses replace the unknown Dirac mass matrix present in the usual seesaw case. This is a considerable reduction of parameters in the neutrino sector and predicts a strong hierarchical pattern in the right handed neutrino mass matrix that is easily derived from a $U(1)_H$ family symmetry. The model is based on the left-right gauge group with an additional $Z_4$ discrete symmetry which gives vanishing neutrino Dirac masses and finite Majorana masses arising at the one loop level. Furthermore, it is one of the few models that naturally allow for large (but not necessarily maximal) mixing angles in the lepton sector. A generalization of the model to the quark sector requires three iso-spin singlet vector-like down type quarks, as in $E_6$. The model predicts an inert doublet type scalar dark matter.