Curvature Expansion for the Gluodynamics String Including Perturbative Gluonic Contributions

Abstract

Perturbation theory, which represents a Wilson loop in the SU(2) gluodynamics as an integral over all the orientations in color space, in the nonperturbative QCD vacuum and the non-Abelian Stokes theorem is 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 worldsheet 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 color "spin" of the representation of the Wilson loop under consideration and a certain path integral, which includes the background Wilson loop average.