Infrared Behavior of the Gluon Propagator on a Large Volume Lattice

TL;DR

This study uses improved lattice actions to analyze the infrared behavior of the gluon propagator, confirming previous findings and demonstrating that infrared suppression is not due to finite volume effects.

Contribution

First calculation of the gluon propagator with an order a^2 improved action and gauge fixing, comparing results across different lattice spacings and volumes.

Findings

Infrared suppression of the gluon propagator is confirmed.

Improved actions yield consistent results with unimproved actions at different lattice spacings.

Infrared behavior is not a finite volume effect.

Abstract

The first calculation of the gluon propagator using an order a^2 improved action with the corresponding order a^2 improved Landau gauge fixing condition is presented. The gluon propagator obtained from the improved action and improved Landau gauge condition is compared with earlier unimproved results on similar physical lattice volumes of 3.2^3 \times 6.4 fm^4. We find agreement between the improved propagator calculated on a coarse lattice with lattice spacing a = 0.35 fm and the unimproved propagator calculated on a fine lattice with spacing a = 0.10 fm. This motivates us to calculate the gluon propagator on a coarse large-volume lattice 5.6^3 \times 11.2 fm^4. The infrared behavior of previous studies is confirmed in this work. The gluon propagator is enhanced at intermediate momenta and suppressed at infrared momenta. Therefore the observed infrared suppression of the Landau gauge gluon propagator is not a finite volume effect.