Curvature Expansion for the Gluodynamics String including Perturbative Gluonic Contributions

TL;DR

This paper derives a correction to the string effective action in SU(2) gluodynamics, accounting for perturbative gluonic contributions and their interaction with the string world sheet, affecting the rigidity term's coupling.

Contribution

It introduces a novel perturbative correction to the string rigidity coupling in gluodynamics, considering nonperturbative effects and the interaction of gluons with the string.

Findings

Correction affects only the rigidity term, not the string tension.

The correction depends on the color representation's spin.

The correction involves a path integral with background Wilson loop averages.

Abstract

Perturbation theory in the nonperturbative QCD vacuum and the non-Abelian Stokes theorem, representing a Wilson loop in the SU(2) gluodynamics as an integral over all the orientations in colour space, are applied to a derivation of the correction to the string effective action in the lowest order in the coupling constant $g$. This correction is due to the interaction of perturbative gluons with the string world sheet and affects only the coupling constant of the rigidity term, while its contribution to the string tension of the Nambu-Goto term vanishes. The obtained correction to the rigidity coupling constant multiplicatively depends on the colour "spin" of the representation of the Wilson loop under consideration and a certain path integral, which includes the background Wilson loop average.