Dipole Moment Bounds on Dark Matter Annihilation

TL;DR

This paper investigates how measurements of lepton dipole moments constrain scalar dark matter models, finding that certain annihilation channels are heavily restricted by experimental bounds.

Contribution

It introduces bounds on dark matter annihilation cross sections derived from loop-induced corrections to lepton dipole moments, highlighting the impact of CP-violating interactions.

Findings

Annihilation to electrons with observable cross section is ruled out.

Annihilation to muons requires CP violation.

Dipole moment constraints significantly limit dark matter models.

Abstract

We consider constraints on simplified models in which scalar dark matter annihilates to light charged leptons through the exchange of charged mediators. We find that loop diagrams will contribute corrections to the magnetic and electric dipole moments of the light charged leptons, and experimental constraints on these corrections place significant bounds on the dark matter annihilation cross section. In particular, annihilation to electrons with an observable cross section would be ruled out, while annihilation to muons is only permitted if the dominant contributions arise from CP-violating interactions.