Inverse seesaw and dark matter in a gauged ${\rm B-L}$ extension with flavour symmetry

TL;DR

This paper introduces a model extending the Standard Model with gauged B-L and L_mu-L_tau symmetries, explaining neutrino masses, dark matter, and the muon g-2 anomaly through inverse seesaw and flavor structures.

Contribution

It presents a novel combined framework linking inverse seesaw neutrino masses, dark matter stability, and muon g-2 within a gauged B-L and L_mu-L_tau symmetry model.

Findings

Dark matter candidate is a stable Dirac fermion.

Model explains neutrino oscillation data and mass hierarchy.

Muon g-2 anomaly is addressed by new gauge boson contributions.

Abstract

We propose a model which generates neutrino masses by the inverse seesaw mechanism, provides a viable dark matter candidate and explains the muon ($g-2$) anomaly. The Standard Model (SM) gauge group is extended with a gauged U(1)$_{\rm B-L}$ as well as a gauged U(1)$_{\rm L_{\mu} - L_{\tau}}$. While U(1)$_{\rm L_{\mu} - L_{\tau}}$ is anomaly free, the anomaly introduced by U(1)$_{\rm B-L}$ is cancelled between the six SM singlet fermions introduced for the inverse seesaw mechanism and four additional chiral fermions introduced in this model. After spontaneous symmetry breaking the four chiral fermionic degrees of freedom combine to give two Dirac states. The lightest Dirac fermion becomes stable and hence the dark matter candidate. We focus on the region of the parameter space where the dark matter annihilates to the right-handed neutrinos, relating the dark matter sector with the neutrino sector. The U(1)$_{\rm L_{\mu} - L_{\tau}}$ gauge symmetry provides a flavour structure to the inverse seesaw framework, successfully explaining the observed neutrino masses and mixings. We study the model parameters in the light of neutrino oscillation data and find correlation between them. Values of some of the model parameters are shown to be mutually exclusive between normal and inverted ordering of the neutrino mass eigenstates. Moreover, the muon ($g-2$) anomaly can be explained by the additional contribution arising from U(1)$_{\rm L_{\mu} - L_{\tau}}$ gauge boson.