# Neutrino-Dark Matter Connections in Gauge Theories

## TL;DR

This paper explores how gauge theories that extend the Standard Model link neutrino mass origins with dark matter properties, providing testable predictions and constraints on model parameters.

## Contribution

It introduces minimal gauge theories connecting neutrino masses with dark matter, deriving bounds on symmetry breaking scales and experimental testability.

## Key findings

- Dirac neutrino scenarios face strong bounds from relativistic species constraints.
- Dark matter candidates emerge naturally from anomaly cancellation in gauge theories.
- Symmetry breaking scales are constrained to the multi-TeV range by cosmological relic density bounds.

## Abstract

We discuss the connection between the origin of neutrino masses and the properties of dark matter candidates in the context of gauge extensions of the Standard Model. We investigate minimal gauge theories for neutrino masses where the neutrinos are predicted to be Dirac or Majorana fermions. We find that the upper bound on the effective number of relativistic species provides a strong constraint in the scenarios with Dirac neutrinos. In the context of theories where the lepton number is a local gauge symmetry spontaneously broken at the low scale, the existence of dark matter is predicted from the condition of anomaly cancellation. Applying the cosmological bound on the dark matter relic density, we find an upper bound on the symmetry breaking scale in the multi-TeV region. These results imply we could hope to test simple gauge theories for neutrino masses at current or future experiments.