Comparable dark matter and baryon abundances with a heavy dark sector

TL;DR

This paper introduces a model where heavy dark baryons in a hidden sector, generated via the Affleck-Dine mechanism, naturally explain the similar observed abundances of dark matter and baryons without requiring coincidental particle masses.

Contribution

It presents a novel scenario with a heavy dark sector and asymmetric reheating that accounts for dark matter and baryon abundance coincidence.

Findings

Dark baryons can be much heavier than visible baryons.

The model predicts uncorrelated dark matter and baryon isocurvature perturbations.

A natural explanation for the similar densities without mass coincidence.

Abstract

We propose a scenario that explains the comparable abundances of dark matter (DM) and baryons without any coincidence in the corresponding particle masses. Here, DM corresponds to heavy "dark baryons" in a hidden MSSM-like dark sector, where the supersymmetry breaking scale can be several orders of magnitude larger than in the visible sector. In both sectors a baryon asymmetry is generated via the Affleck-Dine mechanism, and the smaller dark baryon-to-entropy ratio partially compensates the larger dark baryon masses to give similar densities in the two sectors. The large mass hierarchy also naturally results in an asymmetric reheating of these sequestered sectors. Moreover, this scenario predicts uncorrelated DM and baryon isocurvature perturbations.