Solar seismic model as a new constraint on supersymmetric dark matter

Abstract

If the Milky Way is populated by weakly interacting massive particles (WIMPs) as predicted by cosmological models of the large-scale structure of the Universe and as motivated by supersymmetric models of particle physics (SUSY), the capture of high-mass WIMPs by the Sun would affect the temperature, density and chemical composition of the solar core. This is because WIMPs provide an alternative mechanism for transporting the energy of the core, other than radiative transfer. Helioseismology provides a means for an independent test of the validity of the WIMP-accreting solar models. We use the sound speed and the density profiles inferred from the helioseismic instruments on the Solar and Heliospheric Observatory (SOHO) to discuss the effect of WIMP accretion and annihilation on the evolution of the Sun. The WIMP transport of energy inside the Sun is not negligible for WIMPs with a mass smaller than 60 GeV and annihilating WIMPs with 〈σaυ〈 ∼ 10-27 cm3 s-1. WIMP-accreting models with WIMP masses smaller than 30 GeV are in conflict with the most recent seismic data. We combine our new constraints with the analysis of predicted neutrino fluxes from annihilating WIMPs in the solar core. Working in the framework of the minimal supersymmetric standard model and considering the neutralino as the best dark matter particle candidate, we find that supersymmetric models, consistent with solar seismic data and with recent measurements of dark matter relic density, lead to a measured muon flux on Earth in the range of 1 to 104 km-2 yr-1, for neutralino masses between 30 and 400 GeV. The local change of the solar core structure combined with the increasing accuracy of solar models and the increased sensitivity of future neutrino telescopes presents a clear and distinctive seismic signature which will enable us to set strong independent constraints on the physical properties of dark matter particles.