WIMP Dark Matter from a Natural Discrete Gauge Symmetry in the Standard Model

TL;DR

This paper proposes a natural discrete gauge symmetry within the Standard Model that stabilizes a WIMP dark matter candidate, explaining its relic abundance and compatibility with experimental constraints.

Contribution

It introduces a new discrete gauge symmetry that automatically stabilizes dark matter without ad hoc assumptions, linking anomaly cancellation to dark matter stability.

Findings

Dark matter candidate is stable due to gauge symmetry.

Relic abundance consistent with observations.

Model testable in future experiments.

Abstract

The internal structure of the Standard Model implies a natural $\mathbb{Z}_4 \times \mathbb{Z}_3$ discrete gauge symmetry. Cancellation of the corresponding Dai--Freed anomalies requires the introduction of three right-handed neutrinos and three additional Majorana fermions $\chi_i$. This gauge symmetry forbids the decay of the lightest fermion $\chi_1$ into Standard Model particles, rendering it automatically stable and providing a dark matter candidate without introducing an ad hoc stabilizing symmetry and domain-wall problem. The mass of $\chi_1$ is generated by the vacuum expectation value of a singlet scalar near the electroweak scale, naturally realizing a weakly interacting massive particle (WIMP) freeze-out scenario. Dark matter annihilation proceeds through scalar mediation, allowing the observed relic abundance to be reproduced while remaining consistent with current direct-detection constraints. It naturally realizes the secluded dark matter scenario and can be further tested in the next generation of experiments.