Co-scattering in micrOMEGAs: a case study for the singlet-triplet dark matter model

Understand

In scenarios with very small dark matter (DM) couplings and small mass splittings between the DM and other dark sector particles, so-called "co-scattering" or "conversion-driven freeze-out" can be the dominant mechanism for DM production.

• We present the inclusion of this mechanism in micrOMEGAs together with a case study of the phenomenological implications in the fermionic singlet-triplet model.
• For the latter, we focus on the transition between co-annihilation and co-scattering processes.
• We observe that co-scattering is needed to describe the thermal behaviour of the DM for very small couplings, opening up a new region in the parameter space of the model.