Inelastic nuclear scattering from neutrinos and dark matter

TL;DR

This paper investigates inelastic neutrino and dark matter scattering on nuclei at low energies, providing detailed cross section calculations and highlighting the potential for future experiments to explore these channels.

Contribution

It presents comprehensive nuclear shell model calculations of inelastic scattering cross sections for neutrinos and dark matter on specific nuclei, emphasizing the importance of Gamow-Teller transitions.

Findings

Gamow-Teller transitions dominate the inelastic cross section.

Long-wavelength approximation is effective for neutrino sources.

Future experiments can detect these inelastic scattering channels.

Abstract

Neutrinos with energy of order 10~MeV, such as from pion decay-at-rest sources, are an invaluable tool for studying low-energy neutrino interactions with nuclei -- previously enabling the first measurement of coherent elastic neutrino-nucleus scattering. Beyond elastic scattering, neutrinos and dark matter in this energy range also excite nuclei to its low-lying nuclear states, providing an additional physics channel. Here, we consider neutral-current inelastic neutrino-nucleus and dark matter(DM)-nucleus scattering off $^{40}$Ar, $^{133}$Cs, and $^{127}$I nuclei that are relevant to a number of low-threshold neutrino experiments at pion decay-at-rest facilities. We carry out large scale nuclear shell model calculations of the inelastic cross sections considering the full set of electroweak multipole operators. Our results demonstrate that Gamow-Teller transitions provide the dominant contribution to the cross section and that the long-wavelength limit provides a reasonable approximation to the total cross section for neutrino sources. We show that future experiments will be sensitive to this channel and thus these results provide additional neutrino and DM scattering channels to explore at pion decay-at-rest facilities.