Probing Light Dark Matter via Evaporation from the Sun

TL;DR

This paper explores how underground detectors can detect low-mass dark matter particles evaporating from the sun, providing a new method to constrain dark matter properties by analyzing high-energy recoil events.

Contribution

It introduces a novel approach to probe low-mass dark matter via evaporation from the sun and demonstrates how to determine dark matter parameters from recoil energy spectra.

Findings

Current detectors can constrain low-mass dark matter through evaporation signals.

The recoil energy spectrum uniquely identifies dark matter mass and cross section.

Evaporating dark matter particles have high velocities, enabling detection.

Abstract

Dark matter particles can be captured by the sun with rates that depend on the dark matter mass and the DM-nucleon cross section. However, for masses below $\sim 3.3$ GeV, the captured dark matter particles evaporate, leading to an equilibrium where the rate of captured particles is equal to the rate of evaporating ones. Unlike dark matter particles from the halo, the evaporating dark matter particles have velocities that are not limited to values below the escape velocity of the galaxy. Despite the fact that high velocities are exponentially suppressed, I demonstrate here that current underground detectors have the possibility to probe/constrain low dark matter parameter space by (not)-observing the high energy tail of the evaporating dark matter particles from the sun. I also show that the functional form of the differential rate of counts with respect to the recoil energy in earth based detectors can identify precisely the mass and the cross section of the dark matter particle in this case.