Infrared behaviour of gluon and ghost propagators in QCD in the Landau gauge

TL;DR

This paper investigates the low-momentum behavior of gluon and ghost propagators in Landau gauge QCD using non-perturbative Schwinger-Dyson equations, incorporating Gribov horizon restrictions to improve understanding of confinement.

Contribution

It applies the generalized effective action formalism with Gribov horizon restriction to derive and solve Schwinger-Dyson equations for propagators in Landau gauge QCD, providing both qualitative and quantitative insights.

Findings

Asymptotic behavior of propagators at small momenta is characterized.

Qualitative agreement with previous results is confirmed.

Quantitative differences in coefficients are identified.

Abstract

Non-perturbative formalism of the generalized effective action is used for deriving the Schwinger-Dyson equations. In order to clear the domain of integration in the functional integral from gauge copies a restriction to the Gribov horizon due to Zwanziger is implemented. In this approach an asymptotic behaviour of gluon propagator and propagator of the Faddeev-Popov ghosts at small momenta is studied. Such a behaviour is obtained as a result of solving coupled Schwinger-Dyson equations in zeroth and first-order approximation. The qualitative agreement of these results with the ones obtained before is demonstrated and quantitative difference in some coeffcients is found.