Where do perturbative and non-perturbative QCD meet?

TL;DR

This paper compares perturbative and non-perturbative QCD calculations of the static potential and Wilson loops, showing good agreement at short distances and discussing implications for measuring the QCD running coupling.

Contribution

It provides a detailed perturbative calculation of the static potential and Wilson loops up to second order, and compares these with lattice data for different actions.

Findings

Short distance lattice data aligns well with boosted perturbation theory.

Wilson-type fermions show ~10% agreement between measured and predicted beta-shifts.

Discussion on potential for real-world QCD coupling determination.

Abstract

We computed the static potential and Wilson loops to $O(\alpha^2)$ in perturbation theory for different lattice quark and gluon actions. In general, we find short distance lattice data to be well described by ``boosted perturbation theory''. For Wilson-type fermions at present-day quark masses and lattice spacings agreement within 10% between measured ``$\beta$-shifts'' and those predicted by perturbation theory is found. We comment on prospects for a determination of the real world QCD running coupling.