Solar Reflected Dark Matter under the Influence of a Dark Magnetic Field

Abstract

The scattering of dark matter particles within the Sun's hot plasma can lead to the acceleration of dark matter, producing a high-energy solar-reflected DM flux detectable in ground-based experiments. In the vector portal model, the dark matter has a sub-MeV-scale mass, and interactions between the dark matter and Standard Model particles are mediated by a hidden vector field--referred to as a dark photon--which kinetically mixes with the conventional photon through a small mixing angle. Furthermore, the solar plasma generates intense magnetic fields. Due to the photon-dark photon mixing, this simultaneously sources a ``dark magnetic field". For sufficiently low dark photon masses, this dark magnetic field is capable of deflecting dark matter particles traversing the Sun. We found that if the dark magnetic force is sufficiently strong, the dark magnetic field becomes a wall, preventing the dark matter particles from reaching the deep core region, suppressing their reflected flux. This scenario corrects the sensitivity of the solar-reflected dark matter detection, offering critical insights for ground-based experiments aiming to probe dark matter.