The median recoil direction as a WIMP directional detection signal

Understand

Direct detection experiments have reached the sensitivity required to detect dark matter WIMPs.

• Demonstrating that a putative signal is due to WIMPs, and not backgrounds, is a major challenge however.
• The direction dependence of the WIMP scattering rate provides a potential WIMP `smoking gun'.
• If the WIMP distribution is predominantly smooth, the Galactic recoil distribution is peaked in the direction opposite to the direction of Solar motion.