Dark Matter from Baryon Asymmetry

Abstract

The measured densities of dark and baryonic matter are surprisingly close to each other, even though the baryon asymmetry and the dark matter are usually explained by unrelated mechanisms. We consider a scenario where the dark matter S is produced non-thermally from the decay of a messenger particle X, which carries the baryon number and compensates for the baryon asymmetry in the Universe, thereby establishing a connection between the baryonic and dark matter densities. We propose a simple model to realize this scenario, adding only a light singlet fermion S and a colored particle X which has a mass in the O(TeV) range and a lifetime to appear long-lived in collider detector. Therefore in hadron colliders the signal is similar to that of a stable or long-lived gluino in supersymmetric models.