Resonant Sub-GeV Dirac Dark Matter

TL;DR

This paper investigates a sub-GeV Dirac dark matter model with resonant annihilation via a dark photon, analyzing its detection prospects and compatibility with cosmological and experimental constraints.

Contribution

It provides a comprehensive global analysis of the parameter space, considering multiple experimental bounds and extending to dark matter subcomponents, highlighting viable regions and experimental complementarity.

Findings

Large viable parameter regions remain even with moderate resonance.

Resonant annihilation enhances detection prospects.

Different experiments offer complementary constraints and discovery potential.

Abstract

We study the phenomenology and detection prospects of a sub-GeV Dirac dark matter candidate with resonantly enhanced annihilations via a dark photon mediator. The model evades cosmological constraints on light thermal particles in the early universe while simultaneously being in reach of current and upcoming terrestrial experiments. We conduct a global analysis of the parameter space , considering bounds from accelerator and direct detection experiments, as well as those arising from Big Bang Nucleosynthesis, the Cosmic Microwave Background and dark matter self-interactions. We also extend our discussion to the case of a dark matter subcomponent. We find that large regions of parameter space remain viable even for the case of a moderate resonant enhancement, and demonstrate the complementarity of different experimental strategies for further exploring this scenario.