GRIBOV COPIES IS THE MINIMAL LANDAU GAUGE - THE INFLUENCE ON GLUON AND GHOST PROPAGATORS

We study the influence of Gribov copies on gluon and ghost propagators , evaluated numerically in pure SU(2) lattice gauge theory in the mini mal Landau gauge. Simulations are done at four different values of bet a (namely beta = 0, 0.8, 1.6 and 2.7) and for volumes up to 16(4) (up to 24(4) at beta = 1.6). For the gluon propagator, Gribov noise seems to be of the order of magnitude of the numerical accuracy, even at ver y small values of the coupling beta. On the contrary, for the ghost pr opagator, Gribov noise is clearly observable for the three values of b eta in the strong-coupling regime. In particular, data corresponding t o the minimal Landau gauge are always smaller than those obtained in a generic Landau gauge. This result can be qualitatively explained. (C) 1997 Elsevier Science B.V.