Left-Right model with radiative double seesaw mechanism

TL;DR

This paper introduces an extended Left-Right symmetric model with a global symmetry that leads to a radiative double seesaw mechanism at two loops, explaining neutrino masses, fermion mass hierarchies, and dark matter stability.

Contribution

It presents the first implementation of a radiative double seesaw mechanism with the Dirac submatrix generated at one loop in a Left-Right symmetric framework.

Findings

Successfully reproduces SM fermion mass and mixing patterns.

Compatible with muon g-2, neutrinoless double beta decay, and dark matter constraints.

Provides a novel mechanism for neutrino mass generation at two loops.

Abstract

We propose an extended Left-Right symmetric model with an additional global symmetry $U(1)_X$, which after spontaneous symmetry breaking collapses to a residual subgroup $\mathbb{Z}_2$, ensuring that the light active neutrino masses are generated via a double seesaw mechanism at two loop level, with the Dirac submatrix arising at one loop. It also guarantees one loop level masses for the SM charged fermions lighter than the top quark and protects Dark Matter (DM) candidates of the model. To the best of our knowledge our model has the first implementation of the radiative double seesaw mechanism with the Dirac submatrix generated at one loop level. We show that the model can successfully accommodate the observed pattern of SM fermion masses as well as mixings and is compatible with the constraints arising from the muon $g-2$ anomaly, neutrinoless double beta decay and DM.