Searching for light dark matter at fixed target experiments

Abstract

Nowadays deciphering the fundamental nature of dark matter is one of the foremost open questions in fundamental science. In the last years the dark matter experimental program is primarily focused on weakly-interacting massive particles (WIMPs), but in the recent years many innovative dark matter candidates have emerged. One of the most viable models takes into account DM particles in MeV-GeV mass range that are completely neutral under Standard Model forces, but interact through a new force. Small-scale fixed-target experiments at accelerators have unique sensitivities to fully explore these models. Indeed, accelerator experiments can both produce and detect new particles, such as dark matter and the particles mediating new interactions. This article reviews the various experimental techniques to search for light dark matter, i.e. beam dump, missing mass/energy, and visible mediator search experiments.