A minimal theory of strongly-coupled dark baryons: spectrum predictions from lattice QFT

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.

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