Solar neutrino physics with low-threshold dark matter detectors

TL;DR

This paper proposes a novel analysis method for using low-threshold dark matter detectors to measure Solar neutrino fluxes and probe sterile neutrino properties, achieving high precision and complementing existing searches.

Contribution

It introduces an analysis framework for extracting Solar and neutrino properties from dark matter detector data, including sterile neutrino effects, with potential for high-precision measurements.

Findings

A 1 ton-year Germanium detector could measure the $^8$B Solar neutrino flux normalization to 3% or better.

Combining coherent and elastic scattering data constrains neutrino survival probabilities and active-sterile mixing angles.

The method's sensitivity to sterile neutrinos is competitive with dedicated short baseline experiments.

Abstract

Dark matter detectors will soon be sensitive to Solar neutrinos via two distinct channels: coherent neutrino-nucleus scattering and neutrino electron elastic scattering. We establish an analysis method for extracting Solar model properties and neutrino properties from these measurements, including the possible effects of sterile neutrinos which have been hinted at by some reactor experiments and cosmological measurements. Even including sterile neutrinos, through the coherent scattering channel a 1 ton-year exposure with a low-threshold Germanium detector could improve on the current measurement of the normalization of the $^8$B Solar neutrino flux down to 3% or less. Combining with the elastic scattering data will provide constraints on both the high and low energy survival probability, and will improve on the uncertainty on the active-to-sterile mixing angle by a factor of two. This sensitivity to active-to-sterile transitions is competitive and complementary to forthcoming dedicated short baseline sterile neutrino searches with nuclear decays.