Perturbation theory in the nonperturbative QCD vacuum

TL;DR

This paper develops a perturbation theory framework within the nonperturbative QCD vacuum, demonstrating that the renormalized coupling remains finite at large distances and that infrared renormalons are absent.

Contribution

It introduces a formulation of perturbative expansion in confining QCD that remains finite at large distances and eliminates infrared renormalons.

Findings

Renormalized coupling α_S(R) is finite at large distances.

Infra-red renormalons are absent in the new series.

String tension acts as an infrared regulator.

Abstract

Perturbative expansion in the nonperturbative confining QCD background is formulated. The properly renormalized $\alpha_S(R)$ is shown to be finite at large distances, with the string tension playing the role of an infrared regulator. The infra--red renormalons are shown to be absent in the new perturbation series.