Positron propagation and fluxes from neutralino annihilation in the halo -art. no. 023511.

Supersymmetric neutralinos are one of the most promising candidates for the dark matter in the Universe. If they exist, they should make up some fract ion of the Milky Way halo. We investigate the fluxes of positrons expected at the Earth from neutralino annihilation in the halo. Positron propagation is treated in a diffusion model including energy loss. The positron source function includes contributions from both continuum and monochromatic posi trons. We find that, for a "canonical" halo model and propagation parameter s, the fluxes are generally too low to be visible. Given the large uncertai nties in both propagation and halo structure, it is however possible to obt ain observable fluxes. We also investigate the shapes of the positron spect ra, including tits to a feature indicated by the results of the HEAT experi ment. [S0556-2821(99)00402-6].