The Sun as a sub-GeV Dark Matter Accelerator

TL;DR

This paper explores how the Sun can act as an accelerator for sub-GeV dark matter particles, producing energetic reflected particles that could be detected to probe light dark matter beyond current methods.

Contribution

It derives a new expression for the rate and velocity distribution of solar-reflected dark matter particles, incorporating solar temperature and opacity effects.

Findings

Reflected dark matter particles can reach higher velocities than incoming particles.

Future direct detection experiments could detect these particles to explore new dark matter parameter space.

The Sun can serve as a natural accelerator for light dark matter detection.

Abstract

Sub-GeV halo dark matter that enters the Sun can potentially scatter off hot solar nuclei and be ejected much faster than its incoming velocity. We derive an expression for the rate and velocity distribution of these reflected particles taking into account the Sun's temperature and opacity. We further demonstrate that future direct detection experiments could use these energetic reflected particles to probe light dark matter in parameter space that cannot be accessed via ordinary halo dark matter.