Exploring nu signals in dark matter detectors

TL;DR

This paper explores how new physics could enhance solar neutrino signals in dark matter detectors, potentially explaining observed excesses and affecting future searches by introducing additional backgrounds and signatures.

Contribution

It analyzes the impact of non-standard neutrino interactions, including light force carriers and sterile neutrinos, on neutrino scattering rates and their implications for dark matter detection.

Findings

Neutrino scattering rates can be increased by several orders of magnitude.

Enhanced neutrino signals could explain excess events in CoGeNT and CRESST.

Neutrino signals may exhibit temporal modulation due to various physical effects.

Abstract

We investigate standard and non-standard solar neutrino signals in direct dark matter detection experiments. It is well known that even without new physics, scattering of solar neutrinos on nuclei or electrons is an irreducible background for direct dark matter searches, once these experiments each the ton scale. Here, we entertain the possibility that neutrino interactions are enhanced by new physics, such as new light force carriers (for instance a "dark photon") or neutrino magnetic moments. We consider models with only the three standard neutrino flavors, as well as scenarios with extra sterile neutrinos. We find that low-energy neutrino--electron and neutrino--nucleus scattering rates can be enhanced by several orders of magnitude, potentially enough to explain the event excesses observed in CoGeNT and CRESST. We also investigate temporal modulation in these neutrino signals, which can arise from geometric effects, oscillation physics, non-standard neutrino energy loss, and direction-dependent detection efficiencies. We emphasize that, in addition to providing potential explanations for existing signals, models featuring new physics in the neutrino sector can also be very relevant to future dark matter searches, where, on the one hand, they can be probed and constrained, but on the other hand, their signatures could also be confused with dark matter signals.