IMP Distribution In and Evaporation From The Sun

This paper analyzes the evaporation of WIMPS (weakly interacting massive particles) from the sun, both analytically and numerically. First an analytic approximation is made by defining an appropriate truncation of a MaxwellBoltzmann distribution for the WIMPS and calculating the exact evaporation rate from this distribution due interaction with a truly thermal distribution of nuclei. Then, the actual (non-thermal) distribution of Dirac neutrino WIMPS in the sun is calculated numerically for WIMPS of mass 1 7 GeV. Evaporation from the actual and thermal distributions are compared. It is found that the evaporation mass for a solar life-time is 3.7 GeV and, for an ‘annihilation lifetime,’ 2.9 GeV. These are about 8% lower than the most well-reasoned previous estimate. Submitted to Astrophysical Journal * Work supported by the Department of Energy, contract DE AC03 76SF00515.