Large N-ightmare dark matter

A dark QCD sector is a relatively minimal extension of the Standard Model (SM) that admits Dark Matter (DM) candidates but requires no portal to visible beyond gravitational interactions: "nightmare scenario" for DM detection. We consider secluded containing single flavor light, vector-like quark gauged under $SU(N)$. In large-$N$ limit, this single-flavor theory becomes highly predictive, generating two whose masses and dynamics are described by few parameters: light quark-antiquark bound state, analog $\eta'$ meson, heavy state $N$ quarks, $\Delta^{++}$ baryon. show latter may freeze-in with an abundance independent confinement scale, forming DM-like relics $N \lesssim 10$, while former generate via cannibalization freeze-out. study interplay two-component system determine characteristic ranges dark-visible temperature ratio, admit non-excluded DM, once effects self-interaction constraints bounds on effective degrees freedom at BBN CMB epochs included.