出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：We report on our recent study of the gluon and ghost propagators of pure SU(2) minimal lattice
Landau gauge in the strong-coupling limit. In this limit, we find evidence of the conformal infrared
behaviour of these propagators as predicted by functional continuum methods. However,
in the strong-coupling limit this happens for lattice momenta with a2q2 > 1, in units of the lattice
spacing a. Deviations from conformal scaling for a2q2 < 1 are well parameterised by a transverse
gluon mass. A comparison of various lattice definitions of gauge potentials, all equivalent
in the continuum limit, shows that (a) both the critical exponent and coupling can be extracted
unambiguously from the high-momentum data in the strong-coupling limit, in good agreement
with the continuum predictions; but that on the other hand (b) the massive branch depends on the
definition of lattice gluon fields and is thus not unambiguously defined. We demonstrate that this
ambiguity is also present in the low-momentum region for commonly used values of the lattice
coupling in SU(2).
