Atomic ionization by neutrinos at low energies

Abstract

It is well-known that neutrino-electron scattering at low recoil energies provides sensitivity gain in constraining neutrinos’ magnetic moments and their possible milli-charges. However, in detectors with sub-keV thresholds, the binding effects of electrons become significant. In this talk, we present our recent works of applying ab initio calculations to germanium ionization by neutrinos at low energies. Compared with the conventional differential cross section formulae that were used to derive current experimental bounds, our results with less theoretical uncertainties set a more reliable bound on the neutrino magnetic moment and a more stringent bound on the neutrino milli-charge with current reactor antineutrino data taken from germanium detectors.