Solar reflection of dark matter

The scattering of light dark matter off thermal electrons inside the Sun produces a fast subcomponent of the dark matter flux that may be detectable in underground experiments. We update and extend previous work by analyzing the signatures of dark matter candidates which scatter via light mediators. Using numerical simulations of the dark matter-electron interaction in the solar interior, we determine the energy spectrum of the reflected flux, and calculate the expected rates for direct detection experiments. We find that large Xenon-based experiments (such as XENON1T) provide the strongest direct limits for dark matter masses below a few MeV, reaching a sensitivity to the effective dark matter charge of similar to 10-9e.

Automated summary

By numerically simulating the interaction of dark matter with solar interior electrons, the energy spectrum of the reflected flux can be determined, and the expected rates for direct detection experiments can be calculated. Large Xenon-based experiments offer the strongest direct limits for dark matter masses below a few MeV, with a sensitivity to the effective dark matter charge of approximately 10-9e.