arXiv2015
We discuss two infinite classes of 4d supersymmetric theories, ${T}_N^{(m)}$ and ${\cal U}_N^{(m)}$, labelled by an arbitrary non-negative integer, $m$. The ${T}_N^{(m)}$ theory arises from the 6d, $A_{N-1}$ type ${\cal N}=(2,0)$ theory reduced on a 3-punctured sphere, with normal bundle given by line bundles of degree $(m+1, -m)$; the $m=0$ case is the ${\cal N}=2$ supersymmetric $T_N$ theory. The novelty is the negative-degree line bundle. The ${\cal U}_N^{(m)}$ theories likewise arise from the 6d ${\cal N}=(2,0)$ theory on a 4-punctured sphere, and can be regarded as gluing together two (partially Higgsed) ${T}_N^{(m)}$ theories. The ${T}_N^{(m)}$ and ${\cal U}_N^{(m)}$ theories can be represented, in various duality frames, as quiver gauge theories, built from $T_N$ components via gauging and nilpotent Higgsing. We analyze the RG flow of the ${\cal U}_N^{(m)}$ theories, and find that, for all integer $m>0$, they end up at the same IR SCFT as $SU(N)$ SQCD with $2N$ flavors and quartic superpotential. The ${\cal U}_N^{(m)}$ theories can thus be regarded as an infinite set of UV completions, dual to SQCD with $N_f=2N_c$. The ${\cal U}_N^{(m)}$ duals have different duality frame quiver representations, with $2m+1$ gauge nodes.