Dark matter scattering with pre-supernova neutrinos

Pre-supernova neutrinos, emitted during the last day prior to core collapse of a massive star, could provide a unique probe at MeV energies of scattering interactions between dark matter and neutrinos. Due to attenuation of the flux of electron anti-neutrinos from their scattering on dark matter on the way to Earth, we expect a deficit of inverse beta decay events at large-volume, low-threshold detectors such as KamLAND, JUNO, and Super-K. which we use to derive upper limits on the dark matter-neutrino reduced scattering cross section. Though seemingly weaker than limits from post-bounce supernova neutrino events, these sensitivities provide an important cross-check, could help determine the energy dependence of the cross section, and may even be a distinct probe of certain models. Further, pre-supernova neutrinos may test hints reported of dark matter-neutrino scattering in the early universe suppressing small-scale power as seen in Lyman-alpha data.