Dark matter electromagnetic dipoles: the WIMP expectation

TL;DR

This paper systematically studies the electric and magnetic dipole moments of dark matter induced by four-fermion interactions at one-loop level, exploring their dependence on UV completions and implications for direct detection experiments.

Contribution

It provides a detailed analysis of dark matter dipole moments generated by different UV completions, highlighting their potential detectability in direct detection experiments.

Findings

Magnetic moments typically between 10^{-20} and 10^{-23} ecm or vanish

Dipole moments induce DM-nucleus scattering detectable by current or future experiments

Dependence of moments on UV completion and interaction channels

Abstract

We perform a systematic study of the electric and magnetic dipole moments of dark matter (DM) that are induced at the one-loop level when DM experiences four-fermion interactions with Standard Model (SM) charged fermions. Related to their loop nature these moments can largely depend on the UV completion at the origin of the four-fermion operators. We illustrate this property by considering explicitly two simple ways to generate these operators, from $t$- or $s$-channel tree-level exchange. Fixing the strength of these interactions from the DM relic density constraint, we obtain in particular a magnetic moment that, depending on the interaction considered, lies typically between $10^{-20}$ to $10^{-23}$ ecm or identically vanishes. These non-vanishing values induce, via photon exchange, DM-nucleus scattering cross sections that could be probed by current or near future direct detection experiments.