What it takes to measure a fundamental difference between dark matter and baryons: the halo velocity anisotropy

Understand

Numerous ongoing experiments aim at detecting WIMP dark matter particles from the galactic halo directly through WIMP-nucleon interactions.

• Once such a detection is established a confirmation of the galactic origin of the signal is needed.
• This requires a direction-sensitive detector.
• We show that such a detector can measure the velocity anisotropy beta of the galactic halo.