Kinetic decoupling of neutralino dark matter - art. no. 021302

After neutralinos cease annihilating in the early Universe, they may still scatter elastically from other particles in the primordial plasma. At some point in time, however, they will eventually stop scattering. We calculate the cross sections for neutralino elastic scattering from standard-model pa rticles to determine the time at which this kinetic decoupling occurs. We s how that kinetic decoupling occurs above a temperature T similar to MeV. Th ereafter, neutralinos act as collisionless cold dark matter.