Even lighter particle dark matter

Abstract

We report on recent progress in the search for dark matter particles with masses from 1 Mev c^{-2}−2 to 1 Gev c^{-2}−2. Several dark matter candidates in this mass range are expected to generate measurable electronic-recoil signals in direct-detection experiments. We focus on dark matter particles scattering with electrons in semiconductor detectors since they have fundamentally the highest sensitivity due to their low ionization threshold. Charge-coupled device (CCD) silicon detectors are the leading technology, with significant progress expected in the coming years. We present the status of the CCD program and briefly report on other efforts.