Infrared Gluon and Ghost Propagator Exponents From Lattice QCD

TL;DR

This paper investigates the infrared behavior of gluon and ghost propagators in lattice QCD, finding a power law for gluons consistent with confinement scenarios, but not for ghosts within accessible momentum ranges.

Contribution

It provides lattice QCD measurements of infrared exponents for gluon and ghost propagators, supporting the Gribov-Zwanziger confinement scenario for gluons.

Findings

Gluon propagator follows a power law with exponent ~0.53.

Gluon zero momentum propagator vanishes, supporting confinement.

Ghost propagator does not follow a pure power law in the studied range.

Abstract

The compatibility of the pure power law infrared solution of QCD and lattice data for the gluon and ghost propagators in Landau gauge is discussed. For the gluon propagator, the lattice data is well described by a pure power law with an infrared exponent $\kappa \sim 0.53$, in the Dyson-Schwinger notation. $\kappa$ is measured using a technique that suppresses finite volume effects. This value implies a vanishing zero momentum gluon propagator, in agreement with the Gribov-Zwanziger confinement scenario. For the ghost propagator, the lattice data seem not to follow a pure power law, at least for the range of momenta accessed in our simulation.