Boosted dark matter from diffuse supernova neutrinos

TL;DR

This paper proposes a novel boosted dark matter scenario where interactions with diffuse supernova neutrinos accelerate dark matter particles, explaining the XENON detector's low-energy electron recoil excess better than thermal dark matter models.

Contribution

It introduces a new mechanism for dark matter boosting via supernova neutrino interactions, providing a better fit to experimental data and setting competitive bounds on dark matter properties.

Findings

Boosted dark matter can explain the XENON excess.

Parameter space regions fit the observed data.

Bounds on dark matter cross-section are competitive with other experiments.

Abstract

The XENON collaboration recently reported an excess of electron recoil events in the low energy region with a significance of around $3.3\sigma$. An explanation of this excess in terms of thermal dark matter seems challenging. We propose a scenario where dark matter in the Milky Way halo gets boosted as a result of scattering with the diffuse supernova neutrino background. This interaction can accelerate the dark-matter to semi-relativistic velocities, and this flux, in turn, can scatter with the electrons in the detector, thereby providing a much better fit to the data. We identify regions in the parameter space of dark-matter mass and interaction cross-section which satisfy the excess. Furthermore, considering the data only hypothesis, we also impose bounds on the dark-matter scattering cross-section, which are competitive with bounds from other experiments.