Anomaly-free dark matter models with one-loop neutrino masses and a gauged U(1) symmetry

TL;DR

This paper classifies and analyzes anomaly-free scotogenic models with a local U(1) gauge symmetry that generate neutrino masses and dark matter candidates, avoiding issues of global symmetries and exploring new phenomenological implications.

Contribution

It systematically identifies all possible anomaly-free U(1) charge assignments for dark sector particles in scotogenic models with up to four scalars or fermions, introducing new model classes.

Findings

List of all non-equivalent models with specific charge assignments.

Identification of models with residual discrete symmetries stabilizing dark matter.

Discussion of phenomenological implications of new gauge bosons and dark photons.

Abstract

We systematically study and classify scotogenic models with a local U(1) gauge symmetry. These models give rise to radiative neutrino masses and a stable dark matter candidate, but avoid the theoretical problems of global and discrete symmetries. We restrict the dark sector particle content to up to four scalar or fermionic SU(2) singlets, doublets or triplets and use theoretical arguments based on anomaly freedom, Lorentz and gauge symmetry to find all possible charge assignments of these particles. The U(1) symmetry can be broken by a new Higgs boson to a residual discrete symmetry, that still stabilizes the dark matter candidate. We list the particle content and charge assignments of all non-equivalent models. Specific examples in our class of models that have been studied previously in the literature are the U(1)$_D$ scotogenic and singlet-triplet scalar models breaking to $Z_2$. We also briefly discuss the new phenomenological aspects of our model arising from the presence of a new massless dark photon or massive $Z'$ boson as well as the additional Higgs boson.