Gluon and Ghost Propagators in Landau Gauge on the Lattice

TL;DR

This paper investigates the ultraviolet behavior of ghost and gluon propagators in quenched QCD using lattice simulations, and extracts the QCD scale parameter by matching lattice data with perturbation theory.

Contribution

It provides a lattice-based determination of $ ext{Lambda}_{ ext{QCD}}$ from ghost and gluon propagators, highlighting the dependence on perturbative order and renormalization scheme.

Findings

Estimated $ ext{Lambda}_{ ext{QCD}}$ is approximately 320 MeV.

Values are consistent between ghost and gluon propagators.

Results are sensitive to perturbation theory order and renormalization scheme.

Abstract

We study the ultraviolet behaviour of the ghost and gluon propagators in quenched QCD using lattice simulations. Extrapolation of the lattice data towards the continuum allows to use perturbation theory to extract $\Lambda_{\text{QCD}}$ - the fundamental parameter of the pure gauge theory. The values obtained from the ghost and gluon propagators are coherent. The result for pure gauge SU(3) at three loops is $\Lambda_{\ms}\approx 320\text{MeV}$. However this value does depend strongly upon the order of perturbation theory and upon the renormalisation description of the continuum propagators. Moreover, this value has been obtained without taking into account possible power corrections to the short-distance behaviour of correlation functions.