  Adopting the cooling technique to smooth the discontinuous Z(2) lattice gauge
field, we found that on SU(2) gauge configurations obtained by this smoothing
there exists clear discontinuity of the topological property at almost the same
point as the confinement-deconfinement phase transition of the original Z(2)
gauge theory. This observation suggests the possibility that Z(2) gauge model
might be a testbed for analyzing the relation between the confinement and the
chiral phase transition in which the topological objects are believed to play
crucial roles.
