Dirac neutrinos and gauged lepton number

TL;DR

This paper introduces a novel scotogenic model with gauged lepton number $U(1)_L$ that generates tiny Dirac neutrino masses, stabilizes dark matter, and predicts observable lepton flavor violation.

Contribution

It presents the first model combining gauged lepton number with a one-loop scotogenic mechanism for Dirac neutrino masses, including a dark matter candidate and testable flavor violation predictions.

Findings

Neutrinos acquire tiny Dirac masses via one-loop mechanism.

Dark matter candidate is compatible with current detection and relic abundance.

Lepton flavor violating decays are within experimental reach.

Abstract

We propose the first scotogenic neutrino mass model with gauged lepton number $U(1)_L$, which is spontaneously broken by three units $\Delta L=3$ down to a residual discrete gauge symmetry $\mathbb{Z}_6$. The latter guarantees that neutrinos acquire tiny Dirac masses via a one-loop scotogenic mechanism, simultaneously stabilizing the lightest electrically neutral particle with non-trivial charge under the preserved $\mathbb{Z}_6$ symmetry. In our model there is a scalar particle identified as weakly interacting massive particle dark matter (DM) candidate. We analyzed its compatibility with the existing data on direct DM detection experiments and the DM relic abundance. We also address charged lepton flavor violating decays in our model and find that their predicted rates are within the reach of current experimental sensitivity.