Three-dimensional vacuum domains in four-dimensional SU(2) gluodynamics

Performing lattice simulations of the four-dimensional SU(2) gluodynamics we find evidence for existence of three-dimensional domains whose total volume scales in physical units. Technically, the domains are defined in terms of the minimal density of negative links in Z(2) projection of gauge fields. The volume can be viewed also as the minimal volume bound by the center vortices. We argue that the three-dimensional domains are closely related to confinement.