Earth's Stopping Effect in Directional Dark Matter Detectors

TL;DR

This paper investigates how underground interactions between dark matter particles and nuclei can cause detectable differences in the energy spectrum of particles arriving from different directions, especially for light dark matter candidates.

Contribution

It introduces the concept of Earth's stopping effect in directional dark matter detection and identifies parameter spaces where this effect is observable.

Findings

Underground interactions can cause measurable spectral differences.

Directional detectors can potentially identify dark matter interaction properties.

The effect is significant for light dark matter particles.

Abstract

We explore the stopping effect that results from interactions between dark matter and nuclei as the dark matter particles travel undergound towards the detector. Although this effect is negligible for heavy dark matter particles, there is parameter phase space where the underground interactions of the dark matter particles with the nuclei can create observable differences in the spectrum. Dark matter particles that arrive on the detector from below can have less energy from the ones arriving from above. These differences can be potentially detectable by upcoming directional detectors. This can unveil a large amount of information regarding the type and strength of interactions between nuclei and light dark matter candidates.