As a simple model for dark matter, we propose a QCD-like theory based on SU(2) gauge theory with one flavor of dark quark through a single flavor Dirac fermion in the fundamental representation. We use lattice simulations to investigate the properties of the lowest-lying hadrons. Compared to QCD, the theory has several interesting differences: there are no Goldstone bosons or chiral symmetry restoration when the dark quark becomes massless; the usual global baryon number symmetry is enlarged to SU(2)_B, resembling isospin; and baryons and mesons are unified together in SU(2)_B iso-multiplets.
We argue that the lightest baryon, a vector boson, is a stable dark matter candidate and is a composite realization of the hidden vector dark matter scenario.
The model naturally includes a lighter state, the analog of the eta-prime in QCD, for dark matter to annihilate into to set the relic density via thermal freeze-out. Dark matter baryons may also be asymmetric, strongly self-interacting, or have their relic density set via 3-to-2 cannibalizing transitions.
We discuss some experimental implications of coupling dark baryons to the Higgs portal.
