Strong versus Weak Coupling Confinement in N=2 Supersymmetric QCD

TL;DR

This paper explores the transition from weak to strong coupling in N=2 supersymmetric QCD, revealing how confinement mechanisms shift from monopoles to dyons and analyzing the dual gauge theory description.

Contribution

It demonstrates the duality between weak and strong coupling regimes in N=2 SQCD and clarifies the role of dyons in confinement at strong coupling.

Findings

At weak coupling, monopoles are confined via non-Abelian confinement.

At strong coupling, quark condensates transform into dyon condensates.

The low-energy effective theory at strong coupling is a dual U(N) gauge theory with light dyons.

Abstract

We consider N=2 supersymmetric QCD with the gauge group SU(N_c)=SU(N+1) and N_f number of quark matter multiplets, being perturbed by a small mass term for the adjoint matter, so that its Coulomb branch shrinks to a number of isolated vacua. We discuss the vacuum where r=N quarks develop VEV's for N_f\geq 2N=2N_c-2 (in particular, we focus on the N_f= 2N and N_f= 2N+1 cases). In the equal quark mass limit at large masses this vacuum stays at weak coupling, the low-energy theory has U(N) gauge symmetry and one observes the non-Abelian confinement of monopoles. As we reduce the average quark mass and enter the strong coupling regime the quark condensate transforms into the condensate of dyons. We show that the low energy description in the strongly-coupled domain for the original theory is given by U(N) dual gauge theory of N_f\geq 2N light non-Abelian dyons, where the condensed dyons still cause the confinement of monopoles, and not of the quarks, as can be thought by naive duality.