New signals in dark matter detectors

Abstract. We investigate the scattering of solar neutrinos on electrons and nuclei in dark matter direct detection experiments. The rates of these processes are small in the Standard Model, but can be enhanced by several orders of magnitude if the neutrino sector is slightly non-minimal. This makes even the current generation of dark matter detectors very sensitive to non-standard neutrino physics. Examples discussed here are neutrino magnetic moments and toy models with a simple hidden sector containing a sterile neutrino and a light new gauge boson (“dark photon”). We discuss the expected event spectra and temporal modulation effects, as well as constraints from a variety of astrophysical, cosmological, and laboratory experiments. 1. Neutrino interactions in dark matter detectors It is well known that solar and atmospheric neutrinos constitute an irreducible background to future dark matter searches (see for instance [1]). In particular, neutrinos can scatter on atomic nuclei or electrons, thus mimicking typical dark matter signatures. In this talk, based mostly on ref. [2], we assume that the neutrino sector is slightly non-minimal and show that, in this case, neutrino signals in dark matter detectors can be up to several orders of magnitude stronger than in the Standard Model, enough to make them highly relevant even in the current generation o