Scoto-seesaw model implied by flavor-dependent Abelian gauge charge

TL;DR

This paper proposes a flavor-dependent Abelian gauge extension of the Standard Model that explains fermion generations, neutrino masses, and dark matter, with testable collider signatures and consistency with current experimental constraints.

Contribution

It introduces a novel gauge charge anomaly cancellation mechanism linking fermion generations to neutrino mass generation and dark matter within a unified framework.

Findings

Predicts a new gauge boson observable at colliders.

Provides a viable dark matter candidate consistent with relic density and detection limits.

Explains the origin of three fermion generations through anomaly cancellation.

Abstract

Assuming fundamental fermions possess a new Abelian gauge charge that depends on flavors of both quark and lepton, we obtain a simple extension of the Standard Model, which reveals some new physics insights. The new gauge charge anomaly cancellation not only explains the existence of just three fermion generations as observed but also requires the presence of a unique right-handed neutrino $\nu_R$ with a non-zero new gauge charge. Further, the new gauge charge breaking supplies a residual matter parity, under which the fundamental fermions and $\nu_R$ are even, whereas a right-handed neutrino $N_R$ without the new charge is odd. Consequently, light neutrino masses in our model are generated from the tree-level type-I seesaw mechanism induced by $\nu_R$ and from the one-loop scotogenic contribution accommodated by potential dark matter candidates, $N_R$ and dark scalars, odd under the matter parity. We examine new physics phenomena related to the additional gauge boson, which could be observed at colliders. We analyze the constraints imposed on our model by current experimental limits on neutrino masses, neutral meson oscillations, $B$-meson decays, and charged lepton flavor violating processes. We also investigate the potential dark matter candidates by considering relic density and direct detection.