Production and attenuation of cosmic-ray boosted dark matter

Understand

Light sub-GeV halo dark matter (DM) particles up-scattered by high-energy cosmic-rays (CRs) (referred to as CRDM) can be energetic and become detectable by conventional DM direct detection experiments.

• We perform a refined analysis on the exclusion bounds of the spin-independent DM-nucleon scattering cross section $\sigma_{\chi p}$ in this approach.
• For the exclusion lower bounds, we determine the parameter of the effective distance $D_\text{eff}$ for CRDM production using spatial-dependent CR fluxes and including the contributions from the major heavy CR nuclear species.
• We obtain $D_\text{eff}\simeq 9$ kpc for CRDM particles with kinetic energy above $\sim 1~\text{GeV}$, which pushes the corresponding exclusion lower bounds down to $\sigma_{\chi p} \sim 4\times 10^{-32}~\text{cm}^2$ for DM particle mass at MeV scale and below.