Directional direct detection of light dark matter up-scattered by cosmic rays from direction of the Galactic center

TL;DR

This paper proposes a method to detect MeV-scale dark matter particles that are up-scattered by cosmic rays, focusing on their directional detection from the Galactic center, with simulations showing promising results for future experiments.

Contribution

It introduces a simulation-based approach to identify directional signals of up-scattered dark matter from the Galactic center in future directional detectors.

Findings

Dark matter from the Galactic center can be detected via up-scattering by cosmic rays.

Directional detection can identify dark matter arriving from the Galactic center.

Signatures of up-scattered dark matter can be confirmed with >5σ confidence in future detectors.

Abstract

Dark matter with MeV scale mass is difficult to detect with standard direct search detectors. However, they can be searched for by considering the up-scattering of kinetic energies by cosmic rays. Because the dark matter density is higher in the central region of the Galaxy, the up-scattered dark matter will arrive at Earth from the direction of the Galactic center. Once the dark matter is detected, we can expect to recognize this feature by directional direct detection experiments. In this study, we simulate the nuclear recoils of the up-scattered dark matter and quantitatively reveal that a large amount of this type of dark matter is arriving from the direction of the Galactic center. Also, we have shown that the characteristic signatures of the up-scattered dark matter can be verified with more than 5$\sigma$ confidence levels for the assumed target atoms and future upgrades to directional detectors.