Radiative Corrections to Light Thermal Pseudo-Dirac Dark Matter

Light thermal dark matter has emerged as an attractive theoreticalpossibility and a promising target for discovery at experiments in the nearfuture. Such scenarios generically invoke mediators with very small couplingsto the Standard Model, but moderately strong couplings within the dark sector,calling into question theoretical estimates based on the lowest order ofperturbation theory. As an example, we focus on a scenario in which(pseudo)-Dirac fermion dark matter is connected to the standard model via adark photon charged under a new $U(1)^{\prime}$ extension of the standardmodel, and we investigate the impact of the next-to-leading order correctionsto annihilation and scattering. We find that radiative corrections cansignificantly impact model predictions for the relic density and scatteringcross-section, depending on the strength of the dark sector coupling and ratioof the dark matter to mediator mass. We also show why factorization into theyield parameter $Y$ typically presented in literature leads to imprecision. Ourresults are necessary to accurately map experimental searches into the modelparameter space and assess their ability to reach thermal production targets.