Abstract
Many extensions of the standard model predict superweakly interacting particles, which typically have to decay before big bang nucleosynthesis. The entropy produced in the decays may help to reconcile thermal leptogenesis and big bang nucleosynthesis in scenarios with gravitino dark matter, which is usually difficult due to late decays of the next-to-lightest supersymmetric particle spoiling the predictions of big bang nucleosynthesis. We study this possibility for a general neutralino next-to-lightest supersymmetric particle. We elaborate general properties of the scenario and strong constraints on the entropy-producing particle. As an example, we consider the saxion from the axion multiplet and show that, while enabling a solution of the strong problem, it can also produce a suitable amount of entropy.
- Received 14 October 2010
DOI:https://doi.org/10.1103/PhysRevD.82.115029
© 2010 The American Physical Society