The dimension-two gluon condensate, the ghost-gluon vertex and the Taylor theorem

TL;DR

This paper investigates non-perturbative effects on the Landau gauge ghost-gluon vertex using the dimension-two gluon condensate, successfully explaining lattice data across a range of momenta and proposing a simple model consistent with observations.

Contribution

It demonstrates that dimension-two gluon condensate corrections account for lattice data and introduces a simple vertex model aligned with both intermediate and IR domain results.

Findings

Genuine non-perturbative corrections explain lattice data for the ghost-gluon vertex.

A simple model for the vertex agrees with lattice data across momentum ranges.

The analysis supports the significance of the dimension-two gluon condensate.

Abstract

We study the genuine non-perturbative corrections to the Landau gauge ghost-gluon vertex in terms of the non-vanishing dimension-two gluon condensate, and prove these corrections to give account of current SU(2) lattice data for the vertex with different kinematical configurations in the domain of intermediate momenta, roughly above 2-3 GeV. Based on this OPE analysis, we also present a simple model for the vertex, in acceptable agreement with the lattice data also in the IR domain. The necessity of a non-vanishing dimension-two gluon condensate will be also investigated through the analysis of the running coupling defined by the ghost-gluon vertex in Taylor kinematics.