New Confinement Phases from Singular SCFT

New types of confining phase emerge when some singular SCFT's appearing as infrared fixed points of N=2 supersymmetric QCD (SQCD) are deformed by an N=1 adjoint mass term. We make further checks on the Gaiotto-Seiberg-Tachikawa (GST) description of these vacua against the symmetry and vacuum counting argument, and show that the GST variables correctly describe these systems, brought into confinement phase by the N=1 perturbation. Several examples of such vacua, USp(2N) and SU(N) theories with four flavors and SO(N) theories with one or two flavors, are discussed.