Speaker
Description
The null results in direct detection motivate the exploration of a broader mass range for thermal relic dark matter (DM) candidates. An intuitive new place to extend these models is to consider masses in the MeV to GeV range. One way to do this and avoid bounds from the Cosmic Microwave Background is to introduce a dark sector consisting of a dark mediator and stable DM candidate.
In this project, we explore a way that inelastic cosmic ray collisions can produce a sub-GeV DM candidate with a boosted energy spectrum via proton bremsstrahlung. The production model uses the most recent form factors for dark vector production from initial state radiation including the fitting of resonant structures. The calculation for this production mode is much more similar to an accelerator calculation than other direct detection efforts with the twist of using the cosmic ray spectrum as a varying beam energy. The DM spectrum peaking at higher energies than the galactic halo allows lighter DM candidates to produce significant recoil signals in the detector. In particular, neutrino experiments are more sensitive to these events as the detector recoil energies lie well within the experiment’s higher thresholds. The larger exposure of such experiments gives them more coverage of the phase space for DM models with a dark photon mediator.