Is the Dark Disc contribution to Dark Matter Signals important ?

TL;DR

This paper examines the potential impact of a dark matter dark disc on detection signals, concluding that the effect is mild but can influence interpretations of experimental results like DAMA's annual modulation.

Contribution

It provides an analysis of the dark disc's influence on dark matter detection signals, highlighting subtle effects on local velocity distributions and experimental constraints.

Findings

Dark disc presence may slightly enhance detection signals.

Annual modulation signals like DAMA's are less constrained by other experiments.

Effects on local velocity distributions are subtle but noteworthy.

Abstract

Recent N-body simulations indicate that a thick disc of dark matter, co-rotating with the stellar disc, forms in a galactic halo after a merger at a redshift $z<2$. The existence of such a dark disc component in the Milky Way could affect dramatically dark matter signals in direct and indirect detection. In this letter, we discuss the possible signal enhancement in connection with the characteristics of the local velocity distributions. We argue that the enhancement is rather mild, but some subtle effects may arise. In particular, the annual modulation observed by DAMA becomes less constrained by other direct detection experiments.