Topology and Confinement in SU(N) Gauge Theories

TL;DR

This paper explores the large N limit of SU(N) gauge theories in 3+1 dimensions, providing numerical results for glueball masses and topological susceptibility, and examining k-string tensions to compare with theoretical models.

Contribution

It offers the first lattice-based numerical determination of glueball masses and topological susceptibility in the large N limit of SU(N) gauge theories in 3+1 dimensions.

Findings

Glueball mass ratios approach large N predictions.

Topological susceptibility data supports large N behavior.

K-string tension ratios favor Casimir scaling in some regimes.

Abstract

The large N limit of SU(N) gauge theories in 3+1 dimensions is investigated on the lattice by extrapolating results obtained for $2 \le N \le 5$. A numerical determination of the masses of the lowest-lying glueball states and of the topological susceptibility in the limit $N\to\infty$ is provided. Ratios of the tensions of stable k-strings over the tension of the fundamental string are investigated in various regimes and the results are compared with expectations based on several scenarios -- in particular MQCD and Casimir scaling. While not conclusive at zero temperature in D=3+1, in the other cases investigated our data seem to favour the latter.