Intermediate-Distance String Effects in Wilson Loops\\ via Boundary Action

TL;DR

This paper investigates the QCD flux tube's density profile using the Luscher-Weisz string action with boundary terms, comparing theoretical predictions with lattice data for energy density and potential in SU(2) Yang-Mills theory.

Contribution

It introduces an analysis of the flux tube profile with boundary effects in the LW string model, matching lattice results at small quark separations.

Findings

LW string predictions align with lattice data for flux tube width

Good agreement for Q-Qbar potential at small separations

Boundary terms improve the string model's accuracy

Abstract

The density profile of the QCD flux tube is investigated within the framework of the L\"uscher-Weisz (LW) string action with two boundary terms. The transverse action profile and potential between static quarks are considered using Wilson's loop overlap formalism at zero temperature in SU(2) Yang-Mills theory. We find the predictions of the LW string matching the lattice data for the width of the energy-density and $Q\bar{Q}$ potential up to a small color-source separation of $R=0.32$\,fm.