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