Axino dark matter and baryon number asymmetry from Q-ball decay in gauge mediation

TL;DR

This paper explores how Q-ball decay in gauge-mediated supersymmetry breaking can produce axino dark matter and baryon asymmetry simultaneously, while avoiding conflicts with big bang nucleosynthesis.

Contribution

It presents a scenario where Q-ball decay into axinos and nucleons explains dark matter and baryon asymmetry, with decay timing compatible with nucleosynthesis constraints.

Findings

Q-ball decay occurs before big bang nucleosynthesis.

Decay into supersymmetric particles is suppressed until late decay.

Parameter regions are identified for successful scenario.

Abstract

We investigate the Q-ball decay into the axino dark matter in the gauge-mediated supersymmetry breaking. In our scenario, the Q ball decays mainly into nucleons and partially into axinos to account for the baryon asymmetry and the dark matter of the universe simultaneously. The Q ball decays well before the big bang nucleosynthesis so that it is not affected by the decay. The decay into the supersymmetric particles of the minimal supersymmetric standard model is kinematically prohibited until the very end of the decay, and we could safely make their abundances small enough for the successful big bang nucleosynthesis. We show the regions of axino model parameters and the Q-ball parameters which realize this scenario.