A New Era for Direct Detection Experiments: Probing New Neutrino Physics at Dark Matter Detectors with Solar Neutrinos

Dark matter direct detection experiments are about to hit a complex obstacle - the irreducible background of solar neutrinos. While this will complicate the search for dark matter, it will usher in the beginning of a new search for beyond Standard Model neutrino physics. However, the use of solar neutrinos as a signal of novel physics in these detectors is still in its infancy. To further explore the potential of next-generation and far-future direct detection experiments in this vein, we consider how deviations in the solar neutrino rate can be used as an indirect probe of new physics in the neutrino sector. We consider beyond Standard Model extensions that can serve as solutions to the present tension in the muon's anomalous magnetic moment, as well as the more general framework of neutrino non-standard interactions. In all cases, we find that future direct detection experiments will be able to either probe as-yet unconstrained new neutrino physics or provide us with information complementary to dedicated neutrino experiments. We conclude that direct detection experiments are poised to become key players in the field of neutrino physics, contributing to a compelling research mission beyond their search for dark matter.