How high is the neutrino floor?

TL;DR

This paper analyzes how new physics models in the neutrino sector can significantly raise the neutrino floor, impacting the sensitivity of dark matter detectors, especially for low-mass dark matter particles.

Contribution

It calculates the potential increase of the neutrino floor due to new physics, considering experimental constraints and different mediator types, highlighting implications for dark matter detection.

Findings

Neutrino floor can increase by orders of magnitude for scalar mediators below 10 GeV.

The increase is about a factor of two for vector mediators.

Future low-mass dark matter searches must re-evaluate signals above the neutrino floor.

Abstract

In this paper, we compute the contribution to the coherent elastic neutrino-nucleus scattering cross section from new physics models in the neutrino sector. We use this information to calculate the maximum value of the so-called neutrino floor for direct dark matter detection experiments, which determines when these detectors are sensitive to the neutrino background. After including all relevant experimental constraints in different simplified neutrino models, we have found that the neutrino floor can increase by various orders of magnitude in the region of dark matter masses below 10 GeV in the case of scalar mediators, however, this spectacular enhancement is subject to the re-examination of supernovae bounds. The increase is approximately a factor of two for vector mediators. In the light of these results, future claims by direct detection experiments exploring the low-mass window must be carefully examined if a signal is found well above the expected Standard Model neutrino floor.