WIMP dark matter from a natural discrete gauge symmetry in the Standard Model

A bstract The internal structure of the Standard Model implies a natural ℤ 4 × 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 χ i . This gauge symmetry forbids the decay of the lightest fermion χ 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 χ 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.