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

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 q2 « λ2QCD In the strong-coupling limit, this same behavior is obtained for the larger values of a2q2 (in units of the lattice spacing a), where it is otherwise swamped by the gauge-field dynamics. Deviations for a2q2<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). © 2010 Springer-Verlag / Societá Italiana di Fisica.