Physics from solar neutrinos in dark matter direct detection experiments

TL;DR

Next-generation dark matter detection experiments can measure solar neutrino fluxes, the weak mixing angle, and probe new physics with light mediators by analyzing nuclear and electron recoil rates.

Contribution

This paper provides detailed projections of solar neutrino detection in future dark matter experiments and explores their potential to measure neutrino fluxes, the weak angle, and constrain new physics.

Findings

Solar neutrino event rates can determine the $pp$ flux to 2.5% accuracy.

Future experiments can reduce uncertainties on $pp$ and $^8$B neutrino fluxes below 1%.

Current experiments set bounds on new neutrino interactions and light mediators.

Abstract

The next generation of dark matter direct detection experiments will be sensitive to both coherent neutrino-nucleus and neutrino-electron scattering. This will enable them to explore aspects of solar physics, perform the lowest energy measurement of the weak angle to date, and probe contributions from new theories with light mediators. In this article, we compute the projected nuclear and electron recoil rates expected in several dark matter direct detection experiments due to solar neutrinos, and use these estimates to quantify errors on future measurements of the neutrino fluxes, weak mixing angle and solar observables, as well as to constrain new physics in the neutrino sector. Our analysis shows that the combined rates of solar neutrino events in second generation experiments (SuperCDMS and LZ) can yield a measurement of the $pp$ flux to 2.5% accuracy via electron recoil, and slightly improve the $^8$B flux determination. Assuming a low-mass argon phase, projected tonne-scale experiments like DARWIN can reduce the uncertainty on both the $pp$ and boron-8 neutrino fluxes to below 1%. Finally, we use current results from LUX, SuperCDMS and CDMSlite to set bounds on new interactions between neutrinos and electrons or nuclei, and show that future direct detection experiments can be used to set complementary constraints on the parameter space associated with light mediators.