Abstract:
Nuclear recoils from elastic scattering of sub-GeV dark matter lie below the ionization threshold in silicon. The Migdal Effect—a hypothesized rare process in which an atomic electron is emitted in a low-energy nuclear collision—would make such interactions observable through ionization. This possibility has gained new significance with DAMIC-M, an array of 104 skipper CCDs that will soon provide the world’s largest exposure for dark matter searches in the sub-GeV mass range. In the presence of the Migdal Effect, DAMIC-M’s exposure and single-electron sensitivity would translate into unprecedented reach for dark matter-nucleus scattering, potentially exceeding that of alternative technologies still under development. In this talk, I will present a proposal to measure and calibrate the Migdal Effect in silicon for the first time using a CCD irradiated with neutrons at the CENPA Van de Graaff accelerator.
