Living on the walls of super-QCD

Abstract

We study BPS domain walls in four-dimensional N=1N=1 massive SQCD with gauge group SU(N)SU(N) and F<NF<N flavors. We propose a class of three-dimensional Chern-Simons-matter theories to describe the effective dynamics on the walls. Our proposal passes several checks, including the exact matching between its vacua and the solutions to the four-dimensional BPS domain wall equations, that we solve in the small mass regime. As the flavor mass is varied, domain walls undergo a second-order phase transition, where multiple vacua coalesce into a single one. For special values of the parameters, the phase transition exhibits supersymmetry enhancement. Our proposal includes and extends previous results in the literature, providing a complete picture of BPS domain walls for F<NF<N massive SQCD. A similar picture holds also for SQCD with gauge group Sp(N)Sp(N) and F < N+1F<N+1 flavors.