An explanation for the muon and electron $g-2$ anomalies and dark matter

TL;DR

This paper introduces models with new symmetries to explain the muon and electron g-2 anomalies while providing a dark matter candidate, predicting testable collider signatures and satisfying various experimental constraints.

Contribution

The paper presents novel models with flavor-dependent symmetries that simultaneously address lepton g-2 anomalies and dark matter stability, with testable collider implications.

Findings

Models can produce opposite-sign contributions to muon and electron g-2.

Parameter space exists that explains g-2 anomalies and dark matter relic density.

Higgs-muon coupling can be enhanced by up to 38% over the Standard Model.

Abstract

We propose simple models with a flavor-dependent global $U(1)_\ell$ and a discrete $\mathbb{Z}_2$ symmetries to explain the anomalies in the measured anomalous magnetic dipole moments of muon and electron, $(g-2)_{\mu,e}$, while simultaneously accommodating a dark matter candidate. These new symmetries are introduced not only to avoid the dangerous lepton flavor-violating decays of charged leptons, but also to ensure the stability of the dark matter. Our models can realize the opposite-sign contributions to the muon and electron $g-2$ via one-loop diagrams involving new vector-like leptons. Under the vacuum stability and perturbative unitarity bounds as well as the constraints from the dark matter direct searches and related LHC data, we find suitable parameter space to simultaneously explain $(g-2)_{\mu,e}$ and the relic density. In this parameter space, the coupling of the Higgs boson with muons can be enhanced by up to $\sim 38\%$ from its Standard Model value, which can be tested in future collider experiments.