Scotogenic dark matter from gauged $B-L$

TL;DR

This paper introduces a gauged $B-L$ extension of the Standard Model that naturally stabilizes dark matter and explains neutrino masses via a scotogenic mechanism, predicting a massless neutrino and implications for neutrinoless double beta decay.

Contribution

It presents a novel $U(1)_{B-L}$ gauge extension with anomaly-free fermion content that incorporates a scotogenic mechanism for neutrino mass generation and dark matter stability.

Findings

Model predicts a massless neutrino state.

Dark matter candidate consistent with relic abundance.

Lower bound for neutrinoless double beta decay.

Abstract

We propose a $U(1)_{B-L}$ gauge extension to the SM, in which the dark sector is stabilized through a matter parity symmetry preserved after spontaneous symmetry breaking. The fermion spectrum includes three neutral right-handed fields with $B-L$ charges $(-4,-4, 5)$, that make the model free of gauge anomalies. Two of these neutral fermion fields serve as mediators in a scotogenic mechanism for light-active Majorana neutrino masses. The corresponding neutrino mass matrix has rank 2, predicting a massless state and a lower bound for neutrinoless double beta decay. Regions in the parameter space consistent with dark matter relic abundance are accomplished by the lightest neutral mediator.