WINDOW FOR THE DARK MATTER SOLUTION TO THE SOLAR NEUTRINO PROBLEM

The existence of dark matter particles (cosmions) inside the Sun has been suggested as an explanation for the disagreement between measured and theoretical solar neutrino fluxes. We use the new theoretical results on cosmion capture, evaporation, and energy transport, as well as a modern solar evolution code, to estimate accurately the range of cosmion masses and cross sections which can solve the solar neutrino problem. We find a range somewhat smaller than previously estimated. Including new results from a silicon direct detection experiment, only two extremely small regions of parameter space remain acceptable for the coherent spin-independent cross sections often considered. Cosmions which interact dominantly with hydrogen (spin-dependent interactions) are unaffected by current direct detection searches and remain viable for masses between roughly 2 and 7 GeV and cross sections on protons between roughly 10(-36) and 10(-33.5) cm2.