New features of the gluon and ghost propagator in the infrared region from the Gribov-Zwanziger approach

TL;DR

This paper revises the Gribov-Zwanziger approach to better match recent lattice data, showing that dynamical effects can explain the finite gluon propagator at zero momentum and the non-enhanced ghost propagator.

Contribution

It introduces unexploited dynamical effects within the Gribov-Zwanziger framework to explain new infrared behavior of gluon and ghost propagators.

Findings

Gluon propagator attains a finite nonzero value at zero momentum.

Ghost propagator is not infrared enhanced.

The revised approach aligns well with recent lattice data.

Abstract

So far, the infrared behavior of the gluon and ghost propagator based on the Gribov-Zwanziger approach predicted a positivity violating gluon propagator vanishing at zero momentum, and an infrared enhanced ghost propagator. However, recent data based on huge lattices have revealed a positivity violating gluon propagator which turns out to attain a finite nonvanishing value very close to zero momentum. At the same time the ghost propagator does not seem to be infrared enhanced anymore. We point out that these new features can be accounted for by yet unexploited dynamical effects within the Gribov-Zwanziger approach, leading to an infrared behavior in qualitatively good agreement with the new data.