Dark Matter with Axion-Like Particle Mediators

We study the cosmology and experimental signatures of a dark matter (DM) model where DM interacts with visible matter via an axion-like particle (ALP). We determine the DM abundance from annihilations into ALPs and SM gauge bosons, and we establish which masses and coupling constants produce the observed abundance of DM within the regime of validity of the effective field theory. We then apply constraints from collider searches for ALPs and astrophysical searches for DM annihilation to photons to determine the parameter space still unconstrained by experiment and help guide future searches for DM and ALPs.