BPS domain walls in large-N supersymmetric QCD

We explicitly construct BPS domain walls interpolating between neighboring chirally asymmetric vacua in a model for large-N pure supersymmetric QCD. The BPS equations for the corresponding ℤ_N symmetric order parameter effective Lagrangian reduce to those in the A_N Landau-Ginsburg model assuming that the higher derivative terms in the Kähler potential are suppressed in the large-N limit. These BPS domain walls, which have vanishing width in the large-N limit, can be viewed as supermembranes embedded in a (3 + 1)-dimensional supersymmetric QCD background. The supermembrane couples to a three-form supermultiplet whose components we identify with the composite fields of supersymmetric QCD. We also discuss certain aspects of chromoelectric flux tubes (open strings) ending on these walls which appear to support their interpretation as D-branes.