N=1 deformations and RG flows of N=2 SCFTs

We study certain N = 1 preserving deformations of four-dimensional N = 2 superconformal field theories (SCFTs) with non-abelian flavor symmetry. The deformation is described by adding an A = 1 chiral multiplet transforming in the adjoint representation of the flavor symmetry with a superpotential coupling, and giving a nilpotent vacuum expectation value to the chiral multiplet which breaks the flavor symmetry. This triggers a renormalization group flow to an infrared SCFT. Remarkably, we find classes of theories flow to enhanced N = 2 supersymmetric fixed points in the infrared under the deformation. They include generalized Argyres-Douglas theories and rank-one SCFTs with non-abelian flavor symmetries. Most notably, we find renormalization group flows from the deformed conformal SQCDs to the (A(1), A(n)) Argyres-Douglas theories. From these "Lagrangian descriptions," we compute the full superconformal indices of the (A(1), A(n)) theories and find agreements with the previous results. Furthermore, we study the cases, including the T-N and RON theories of class S and some of rank-one SCFTs, where the deformation gives genuine N = 1 fixed points.