BPS Domain Walls in Large N Supersymmetric QCD

TL;DR

This paper constructs explicit BPS domain walls in large N supersymmetric QCD, revealing their structure as supermembranes and exploring their relation to D-branes and flux tubes.

Contribution

It provides a detailed construction of BPS domain walls in large N supersymmetric QCD and interprets them as supermembranes coupled to a three-form supermultiplet.

Findings

BPS domain walls have vanishing width at large N.

Domain walls can be viewed as supermembranes embedded in 4D space.

Evidence suggests these walls behave like D-branes supporting flux tubes.

Abstract

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 ${\bf Z}_N$ symmetric order parameter effective Lagrangian reduce to those in the $A_N$ Landau-Ginsburg model assuming that the higher derivative terms in the K{\"a}hler 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.