PNNL

Abstract

We present a search for dark matter particles with sub- GeV/c2 masses whose interactions have final state electrons using the DarkSide-50 experiment’s (12 306± 184) kg d low-radioactivity liquid argon exposure. By analyzing the ionization signals, we exclude new parameter space for the dark matter-electron cross section ¯se, the axioelectric coupling constant gAe, and the dark photon kinetic mixing parameter ?. We also set the first dark matter direct-detection constraints on the mixing angle |Ue4|2 for keV/c2 sterile neutrinos.