Dark unification: A UV-complete theory of asymmetric dark matter

Abstract

Motivated by the observed ratio of dark matter to baryon mass densities, ρ_D/ρ_B≃5, we propose a theory of dark-color unification. In this theory, the dark to visible baryon masses are fixed by the ratio of dark to visible confinement scales, which are determined to be nearby in mass through the unification of the dark and visible gauge theories at a high scale. Together with a mechanism for dark baryogenesis, which arises naturally from the grand unification sector, the mass densities of the two sectors must be nearby, explaining the observed mass density of dark matter. We focus on the simplest possible example of such a theory, where the Standard Model color SU(3)_C is unified with the dark color SU(2)_D into SU(5) at an intermediate scale of around 10⁸–10⁹  GeV. The dark baryon consists of two dark quarks in an isotriplet configuration. There are a range of important cosmological, astrophysical, and collider signatures to explore, including dark matter self-interactions, early matter domination from the dark hadrons, gravitational wave signatures from the hidden sector phase transition, contributions to flavor observables, as well as Hidden-Valley-like signatures at colliders.