Revising inelastic dark matter direct detection by including the cosmic ray acceleration

Abstract

The null signal from collider and dark matter (DM) direct detector experiments makes the interaction between the DM and visible matter too tiny to reproduce the correct relic density for many thermal DM models. One of the most popular explanations is the inelastic DM scenario, allowing the coannihilation between two almost degenerated states in the dark sector. Unfortunately, the virialized DM component from the nearby halo is non-relativistic and not able to excite the DM ground state even if the relevant couplings can be considerable. Thus, the DM with either the light mass or large mass splitting can evade the traditional virialized DM searches. In this work, we connect the concept of cosmic-ray accelerated DM in our Milky Way (MW) and the direct detection of the inelastic scattering in the underground detectors to explore spectra that are resulted from several interaction types of the inelastic DM. We find that the mass splitting δ < O(1 GeV) can still be reachable for the cosmic ray accelerated DM with mass range 1 MeV < m χ 1 < 100 GeV and sub-GeV light mediator, by using the latest PandaX-4T data, even though we conservatively take the astrophysical parameter (effective length) D eff = 1 kpc.

Revisiting the Fermionic Dark Matter Absorption on Electron Target

“…Several possibilities have been discussed in the literature. The nonrelativistic DM particles can be boosted by the cosmic rays to gain sufficient energy [49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64]. This cosmic ray boosted DM (CRDM) scenario can happen as long as DM interacts with SM particles which is exactly the foundation of DM direct detection.…”