Precise dark matter relic abundance in decoupled sectors

Understand

Dark matter (DM) as a thermal relic of the primordial plasma is increasingly pressured by direct and indirect searches, while the same production mechanism in a decoupled sector is much less constrained.

• We extend the standard treatment of the freeze-out process to such scenarios and perform precision calculations of the annihilation cross-section required to match the observed DM abundance.
• We demonstrate that the difference to the canonical value of this 'thermal cross-section' is generally sizeable, and can reach orders of magnitude.
• Our results directly impact the interpretation of DM searches in hidden sector scenarios.