Ring-like features in directional dark matter detection

TL;DR

This paper introduces a new directional dark matter detection signature where WIMP-induced recoil rates form a ring pattern, which varies with WIMP mass and velocity, potentially aiding in identifying WIMP properties.

Contribution

It presents the concept of a recoil rate ring in directional detection, highlighting its dependence on WIMP mass and velocity, offering a novel detection signature.

Findings

Recoil rate peaks form a ring at certain energies and angles.

Ring size depends on WIMP mass and velocity dispersion.

Ring detection could help estimate WIMP mass range.

Abstract

We discuss a novel dark matter signature relevant for directional detection of Weakly Interacting Massive Particles (WIMPs). For heavy enough WIMPs and low enough recoil energies, the maximum of the recoil rate is not in the direction of the average WIMP arrival direction but in a ring around it at an angular radius that increases with the WIMP mass and can approach 90 degrees at very low energies. The ring is easier to detect for smaller WIMP velocity dispersion and larger average WIMP velocities relative to the detector. In principle the ring could be used as an additional indication of the WIMP mass range.