Baryons and Flux Tubes in Confining Gauge Theories from Brane Actions

TL;DR

This paper uses the AdS/CFT correspondence to analyze baryon configurations in large N non-supersymmetric SU(N) gauge theories, revealing how flux tubes and baryonic states behave in confining regimes.

Contribution

It constructs explicit brane embeddings describing baryons and flux tubes in non-supersymmetric gauge theories, including the novel $ u$-dependent tension of the flux tube.

Findings

Flux tube tension depends nontrivially on quark separation fraction $ u$

Baryonic states are modeled by D5-brane embeddings in near-horizon geometry

The approach applies to both three-dimensional and four-dimensional confining theories

Abstract

We study baryon configurations in large N non-supersymmetric SU(N) gauge theories, applying the AdS/CFT correspondence. Using the D5-brane worldvolume theory in the near-horizon geometry of non-extremal D3-branes, we find embeddings which describe baryonic states in three-dimensional QCD. In particular, we construct solutions corresponding to a baryon made of N quarks, and study what happens when some fraction $\nu$ of the total number of quarks are bodily moved to a large spatial separation from the others. The individual clumps of quarks are represented by Born-Infeld string tubes obtained from a D5-brane whose spatial section has topology $R \times S^4$. They are connected by a confining color flux tube, described by a portion of the fivebrane that runs very close and parallel to the horizon. We find that this flux tube has a tension with a nontrivial $\nu$-dependence (not previously obtained by other methods). A similar picture is presented for the four-dimensional case.