Correlation functions of Polyakov loops at tree level

TL;DR

This paper calculates Polyakov loop correlation functions at tree level for SU(N_c) gauge theories in two cases, revealing different short-distance behaviors and suggesting non-Coulombic effects are due to the planar limit.

Contribution

It explicitly computes tree-level correlation functions for Polyakov loops in SU(2) and large N_c, highlighting differences in short-distance behavior.

Findings

For N_c=2, correlation behaves as 1/x at short distances.

For N_c=∞, correlation behaves as 1/√x at short distances.

Non-Coulombic behavior may be an artifact of the planar limit.

Abstract

We compute the correlation functions of Polyakov loops in $SU(N_c)$ gauge theories by explicitly summing all diagrams at tree level in two special cases, for $N_c = 2$ and $N_c = \infty$. When $N_c =2$ we find the expected we find Coulomb-like behavior at short distances, $\sim 1/x$ as the distance $x \rightarrow 0$. In the planar limit at $N_c = \infty$ we find a weaker singularity, $\sim 1/\sqrt{x}$ as $x \rightarrow 0$. In each case, at short distances the behavior of the correlation functions between two Polyakov loops, and the corresponding Wilson loop, are the same. We suggest that such non-Coulombic behavior is an artifact of the planar limit.