Using the chiral algebra bootstrap, we revisit the simplest Argyres-Douglas (AD) generalization of Argyres-Seiberg S-duality. We argue that the exotic AD superconformal field theory (SCFT), {mathcal{T}}_{3,frac{3}{2}} , emerging in this duality splits into a free piece and an interacting piece, {mathcal{T}}_X , even though this factorization seems invisible in the Seiberg-Witten (SW) curve derived from the corresponding M5-brane construction. Without a Lagrangian, an associated topological field theory, a BPS spectrum, or even an SW curve, we nonetheless obtain exact information about {mathcal{T}}_X by bootstrapping its chiral algebra, {}_{mathcal{X}}left({mathcal{T}}_Xright) , and finding the corresponding vacuum character in terms of Affine Kac-Moody characters. By a standard 4D/2D correspondence, this result gives us the Schur index for {mathcal{T}}_X and, by studying this quantity in the limit of small S1, we make contact with a proposed S1 reduction. Along the way, we discuss various properties of {mathcal{T}}_X : as an mathcal{N} = 1 theory, it has flavor symmetry SU(3) × SU(2) × U(1), the central charge of {}_{mathcal{X}}left({mathcal{T}}_Xright) matches the central charge of the bc ghosts in bosonic string theory, and its global SU(2) symmetry has a Witten anomaly. This anomaly does not prevent us from building conformal manifolds out of arbitrary numbers of {mathcal{T}}_X theories (giving us a surprisingly close AD relative of Gaiotto’s TN theories), but it does lead to some open questions in the context of the chiral algebra/4D mathcal{N} =2SCFT correspondence.
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