Into the wedge of N = 2 superconformal gauge theories

We study 1/4-BPS Wilson loops in four-dimensional SU(N) N = 2 super-Yang-Mills theories with conformal matter in an arbitrary representation R. These operators are formed of two meridians on the two-sphere separated by an arbitrary opening angle. We conjecture that these observables are encoded in a modification of Pestun’s matrix model. The matrix representation of these operators resembles that of the 1/2-BPS circular Wilson loop, differing only for a rescaling in the exponent. We compare the matrix model predictions with an explicit three-loop calculation in flat space based on standard Feynman-diagram techniques, finding perfect agreement. Finally, exploiting the matrix model representation of these Wilson loops, we study the large-N limit at strong coupling of N = 2 superconformal QCD, finding a surprising transition in the vacuum expectation value for a critical opening angle.