Axino dark matter from Q-balls in Affleck-Dine baryogenesis and the $\hat{I}{\text{c◯}}_b-\hat{I}{\text{c◯}}_{DM}$ coincidence problem

Abstract

We show that the $\hat{I}{\text{c◯}}_b-\hat{I}{\text{c◯}}_{DM}$ coincidence can naturally be explained in a framework where axino cold dark matter is predominantly produced in non-thermal processes involving decays of Q-balls formed in Affleck-Dinebaryogenesis. In this approach the similarity between $\hat{I}{\text{c◯}}_b$ and $\hat{I}{\text{c◯}}_{DM}$ is a direct consequence of the (sub-)GeV scale of the mass of the axino.

4 pages, no figure, final PRL version