Semi-analytic treatments of weakly interacting massive particle (WIMP) orbits in
the solar system (e.g., Damour
& Krauss 1999, Gould 1991, Lundberg & Edsjo 2004) suggest that the WIMPs
bound to solar system may
enhance the direct detection rate relative to that of the unbound population by
up to a factor of order unity, as
well as boost the flux of neutrinos from WIMP annihilation in the Earth up to
two orders of magnitude. Given
these intriguing implications, it is worthwhile to check the semi-analytic
approximations with numerical
integrations of particle orbits in the solar system. We present the results of a
suite of numerical experiments to
explore the size of the bound WIMP population as a function of WIMP mass and
the elastic scattering cross section
with baryonic matter. For regions of WIMP parameter space not yet excluded by
experiments, we find that the
bound WIMP population enhances the direct detection rate by at most $\approx
1\%$ relative to the halo WIMP
rate. It is unlikely that neutrinos from WIMP annihilation in the Earth will be
observed in upcoming km$^3$-
scale neutrino telescopes. The event rate from neutrinos from WIMP
annihilation in the Sun will depend on the
WIMP mass and elastic cross section in ways that have not been previously
explored. |