Exodus: Hidden origin of dark matter and baryons

TL;DR

This paper introduces a new framework where dark matter and baryon densities originate from decays of a hidden sector, allowing for different dark matter candidates and providing a supersymmetric model consistent with observed relic densities.

Contribution

It presents a novel mechanism linking dark matter and baryon asymmetry through hidden sector decays, with a concrete supersymmetric implementation.

Findings

The model can produce the correct dark matter relic density.

Dark matter can be a scalar or Majorana fermion, differing from asymmetric models.

Supersymmetric realization with bino LSP is feasible.

Abstract

We propose a new framework for explaining the proximity of the baryon and dark matter relic densities \Omega_{DM} \approx 5\Omega_B. The scenario assumes that the number density of the observed dark matter states is generated due to decays from a second hidden sector which simultaneously generates the baryon asymmetry. In contrast to asymmetric dark matter models, the dark matter can be a real scalar or Majorana fermion and thus presents distinct phenomenology. We discuss aspects of model building and general constraints in this framework. We present a simple supersymmetric implementation of this mechanism and show that it can be used to obtain the correct dark matter relic density for a bino LSP.