Enhanced prospects for direct detection of inelastic dark matter from a non-galactic diffuse component

Abstract

In some scenarios, the dark matter particle predominantly scatters inelastically with the target, producing a heavier neutral particle in the final state. In this class of scenarios, the reach in parameter space of direct detection experiments is limited by the velocity of the dark matter particle, usually taken as the escape velocity from the Milky Way. On the other hand, it has been argued that a fraction of the dark matter particles in the Solar System could be bound to the envelope of the Local Group or to the Virgo Supercluster, and not to our Galaxy, and therefore could carry velocities larger than the escape velocity from the Milky Way. In this paper we estimate the enhancement in sensitivity of current direct detection experiments to inelastic dark matter scatterings with nucleons or electrons due to the non-galactic diffuse components, and we discuss the implications for some well motivated models.