Constraints on Light Dark Matter Particles Interacting with Electrons from DAMIC at SNOLAB

We report direct-detection constraints on light dark matter particles interacting with electrons. The results are based on a method that exploits the extremely low levels of leakage current of the DAMIC detector at SNOLAB of 2 - 6 ×10^{-22A cm -2} . We evaluate the charge distribution of pixels that collect <10 e^- for contributions beyond the leakage current that may be attributed to dark matter interactions. Constraints are placed on so-far unexplored parameter space for dark matter masses between 0.6 and 100 MeV c^-2 . We also present new constraints on hidden-photon dark matter with masses in the range 1.2 - 30 eV c^-2 .