Description
In the context of direct detection experiments, dark matter interactions with Standard Model particles are often described using non-renormalizable operators in an Effective Field Theory (EFT). The UV models that give rise to these EFT operators can sometimes be better constrained through direct searches for evidence of the heavy states which are integrated out, ruling out parameter space that is otherwise assumed to be open. As a case study, we discuss dark matter coupling to the photon via an anapole moment, the only possible electromagnetic moment for Majorana fermions. We review different UV-completions, including scenarios reminiscent of a sfermion and neutralino, as well as a dark sector including a dark photon and milli-charged particle. We discuss collider, direct- and indirect-detection, and cosmological constraints, as well as theory targets for different production mechanisms, including a new prediction for a combined IR freeze-in/freeze-out in the dark sector scenario at sub-GeV masses.