Phase space distribution and directional direct detection of dark matter weakly interacting massive particles

There is overwhelming evidence for dark matter in the Universe. Particles of a new kind are excellent dark matter candidates, but they have not been detected yet. Dozens of detectors are attempting to find them directly, analyzing their interaction with target nuclei underground, and indirectly, searching for their annihilation products. New techniques for the laboratory direct detection of dark matter weakly interacting massive particles (WIMPs) are sensitive to the recoil direction of the struck nuclei. This thesis is devoted to a study of the distribution and directional direct detection of dark matter WIMPs.; We analyze the effect of the Sun's gravitational field on the phase-space distribution of unbound dark matter particles approaching the Earth. We determine the phase-space distribution of the flow both numerically, tracing particle trajectories back in time, and analytically, providing a simple correct relation between the velocity of particles at infinity and at the Earth. We use our results to produce sky maps of the distribution of arrival directions of dark matter particles on Earth at various times of the year. We assume various Maxwellian velocity distributions at infinity describing the standard dark halo and streams of dark matter. We illustrate the formation of a ring, analogous to the Einstein ring, when the Earth is directly downstream of the Sun. We resolve discrepancies in previous analyses of the flow of collisionless dark matter particles in the Sun's gravitational field.; We compute and compare the directional recoil rates for several WIMP velocity distributions including the standard dark halo and anisotropic models such as Sikivie's late-infall halo model and logarithmic-ellipsoidal models. Since some detectors may be unable to distinguish the beginning of the recoil track from its end, we introduce a "folded" directional recoil rate that resolve this lack of head-tail discrimination. We compute the CS2 and CF 4 exposures required to distinguish a signal from an isotropic background noise, and find that the "folded" directional recoil rate is effective for the standard dark halo and some but not all anisotropic models.