Eur. Phys. J. C (2010) 68: 487-503
https://doi.org/10.1140/epjc/s10052-010-1381-8

Regular Article - Theoretical Physics

Infrared exponents and the strong-coupling limit in lattice Landau gauge

Centre for the Subatomic Structure of Matter, School of Chemistry & Physics, The University of Adelaide, Adelaide, SA, 5005, Australia

^* e-mail: andre.sternbeck@physik.uni-regensburg.de

Received: 17 December 2009
Revised: 9 April 2010
Published online: 9 July 2010

Abstract

We study the gluon and ghost propagators of lattice Landau gauge in the strong-coupling limit β=0 in pure SU(2) lattice gauge theory to find evidence of the conformal infrared behavior of these propagators as predicted by a variety of functional continuum methods for asymptotically small momenta . In the strong-coupling limit, this same behavior is obtained for the larger values of a ² q ² (in units of the lattice spacing a), where it is otherwise swamped by the gauge-field dynamics. Deviations for a ² q ²<1 are well parameterized by a transverse gluon mass ∝1/a. Perhaps unexpectedly, these deviations are thus no finite-volume effect but persist in the infinite-volume limit. They furthermore depend on the definition of gauge fields on the lattice, while the asymptotic conformal behavior does not. We also comment on a misinterpretation of our results by Cucchieri and Mendes (Phys. Rev. D 81:016005, 2010).