Effects of halo triaxiality, anisotropy and small scale clumping on WIMP direct detection exclusion limits

Abstract

Weakly Interacting Massive Particle (WIMP) direct detection experiments are closing in on the region of parameter space where neutralinos may constitute the Galactic halo dark matter. Numerical simulations and observations of galaxy halos indicate that the standard Maxwellian halo model is likely to be a poor approximation to the dark matter distribution. We examine how halo models with triaxiality and/or velocity anisotropy affect exclusion limits, before discussing the consequences of the possible survival of small scale clumps.