Thermal Goldstino Production with Low Reheating Temperatures

Understand

We discuss thermal production of (pseudo) goldstinos, the Goldstone fermions emerging from (multiple) SUSY breaking sectors, when the reheating temperature is well below the superpartner masses.

• In such a case, the production during matter-dominated era induced by inflaton decay stage is more important than after reheating.
• Depending on the SUSY breaking scale, goldstinos are produced by freeze-in or freeze-out mechanism via $1\to 2$ decays and inverse decays.
• We solve the Boltzmann equation for the momentum distribution function of the goldstino.In the freeze-out case, goldstinos maintain chemical equilibrium far after they are kinetically decoupled from the thermal bath, and consequently goldstinos with different momentum decouple at different temperatures.