Is a co-rotating Dark Disk a threat to Dark Matter Directional Detection ?

TL;DR

This paper investigates whether a co-rotating Dark Disk could undermine the effectiveness of directional Dark Matter detection, concluding that it likely does not significantly impact detection prospects.

Contribution

The study evaluates the impact of a co-rotating Dark Disk on directional detection sensitivity, demonstrating minimal effect even under extreme model parameters.

Findings

Dark Disk contribution can be up to 50% of local Dark Matter density

Dark Disk models do not significantly reduce detection sensitivity

Directional detection remains robust against Dark Disk substructure

Abstract

Recent N-Body simulations are in favor of the presence of a co-rotating Dark Disk that might contribute significantly (10%-50%) to the local Dark Matter density. Such substructure could have dramatic effect on directional detection. Indeed, in the case of a null lag velocity, one expects an isotropic WIMP velocity distribution arising from the Dark Disk contribution, which might weaken the strong angular signature expected in directional detection. For a wide range of Dark Disk parameters, we evaluate in this Letter the effect of such dark component on the discovery potential of upcoming directional detectors. As a conclusion of our study, using only the angular distribution of nuclear recoils, we show that Dark Disk models as suggested by recent N-Body simulations will not affect significantly the Dark Matter reach of directional detection, even in extreme configurations.