New Observables for Pseudo-Millicharged Dark Matter

Among the broad landscape of models of Dark Matter, one of the simplest consists of a particle coupled to a dark photon which is kinetically mixed with the Standard Model photon. If the Dark Matter mass is below an MeV, the dark photon is constrained to be extremely light. We will argue that this leads to the charged Dark Matter being pseudo-millicharged under Electromagnetism on experimental length scales. This in turn will lead to a variety of new observables which can be tested for. We will present some new experimental ideas, focusing on a proposal which has the capability of probing a wide range of the sub-MeV Dark Matter parameter space.