Disentangling Dark Matter Dynamics with Directional Detection

TL;DR

This paper demonstrates that directional detection experiments can distinguish between elastic and inelastic dark matter scattering, revealing the underlying dark matter dynamics that are otherwise indistinguishable in recoil spectra.

Contribution

It introduces the use of directional detection to differentiate elastic and inelastic dark matter interactions, providing a new method to uncover dark matter sector structures.

Findings

Directional detection can separate elastic and inelastic scattering events.

Elastic and inelastic interactions produce similar recoil spectra without directional information.

Directional detection enhances understanding of dark matter interaction mechanisms.

Abstract

Inelastic dark matter reconciles the DAMA anomaly with other null direct detection experiments and points to a non-minimal structure in the dark matter sector. In addition to the dominant inelastic interaction, dark matter scattering may have a subdominant elastic component. If these elastic interactions are suppressed at low momentum transfer, they will have similar nuclear recoil spectra to inelastic scattering events. While upcoming direct detection experiments will see strong signals from such models, they may not be able to unambiguously determine the presence of the subdominant elastic scattering from the recoil spectra alone. We show that directional detection experiments can separate elastic and inelastic scattering events and discover the underlying dynamics of dark matter models.