Elastic scattering of supernova neutrinos with electrons in xenon

Abstract

Neutrinos from a Galactic core collapse supernova can undergo elastic scattering with electrons in xenon atoms in liquid xenon based dark matter detectors giving rise to electrons of kinetic energy up to a few MeV. We calculate the scattered electron spectrum and the number of such elastic scattering events expected for a typical Galactic core collapse supernova in a xenon target. Although the expected number of events is small (compared to, for example, inelastic neutrino-nucleus charged current interaction with xenon nuclei, that also gives rise to final state electrons), the distinct spectral shape of the scattered electrons may allow identification of the elastic scattering events. Further, while the process is dominated by neutrinos and antineutrinos of electron flavor, it receives contributions from all the six neutrino species. Identification of the electron scattering events may, therefore, allow an estimation of the relative fractions of the total supernova explosion energy going into electron flavored and non-electron flavored neutrinos.