- Accepted Paper
Constraints on sub-MeV dark matter from solar reflection with DAMIC-M
Phys. Rev. D - Accepted 2 October, 2026
DOI: https://doi.org/10.1103/1h93-cx4x
Phys. Rev. D - Accepted 2 October, 2026
DOI: https://doi.org/10.1103/1h93-cx4x
The Sun acts as a natural dark matter accelerator. Galactic halo particles scattering in the solar plasma emerge with velocities well beyond the Galactic escape speed, providing a boosted flux that extends the kinematic reach of direct detection experiments into the sub-MeV mass regime. We present constraints on solar-reflected dark matter (SRDM) from the DAMIC-M prototype detector using ∼1.3 kg-day of data acquired with silicon skipper charge-coupled devices (CCDs) at the Modane Underground Laboratory. Exploiting the spatial diffusion signature of low-energy electron recoils, we derive 90% C.L. upper limits on the DM-electron scattering cross section for both heavy- and ultralight-mediator benchmarks, reaching ¯ σe ∼ 10−36cm2 at 0.1 MeV. For the ultralight mediator, our limits are competitive with the world-leading constraints. These results probe the parameter space between stellar-cooling bounds and terrestrial limits from standard halo searches, a region inaccessible to direct detection experiments relying solely on the standard halo flux.
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