Sub-GeV dark matter at accelerators

Abstract

Motivations for studying light MeV-to-GeV mass dark matter scenarios and opportunities for probing these models with high intensity fixed target experiments are reviewed. Attention is focussed on the lower O(MeV) end of the thermal relic mass window, as relevant for high-intensity accelerators probing nuclear structure, and the complexities of models in this mass range due to cosmological constraints such as the bound on N eff. Existing limits, including those from direct detection electron-scattering experiments sensitive to a sub-leading but more energetic solar reflected component of the dark matter halo distribution, are also reviewed.