  We evaluate the so-called Bose-ghost propagator Q(p^2) for SU(2) gauge theory
in minimal Landau gauge, considering lattice volumes up to 120^4 and physical
lattice extents up to 13.5 f. In particular, we investigate discretization
effects, as well as the infinite-volume and continuum limits. We recall that a
nonzero value for this quantity provides direct evidence of BRST-symmetry
breaking, related to the restriction of the functional measure to the first
Gribov region. Our results show that the prediction (from cluster
decomposition) for Q(p^2) in terms of gluon and ghost propagators is better
satisfied as the continuum limit is approached.
