On Dirac sheet configurations of SU(2) lattice fields

Finite temperature Euclidean SU(2) lattice gauge fields close to the deconfinement phase transition are subjected to cooling. We find relatively stable or absolutely stable configurations with an action below the one-instanton action both in the deconfinement and the confinement phases. In this paper we attempt to interpret these lowest action configurations. Their action is purely magnetic and amounts to , where N_t (N_s) is the timelike (spacelike) lattice size, while the topological charge vanishes. In the confined phase part of the corresponding lattice configurations turns out to be absolutely stable with respect to the cooling process in which case Abelian projection reveals a homogeneous, purely Abelian magnetic field closed over the boundary in one of the spatial directions. Referring to the dyonic structure established for the confinement phase near T_c and based on the observation made for this phase that such events below the instanton action S_inst emerge from dyon-antidyon annihilation, the question of the stability (metastability) is discussed for both phases. The hypothetically different dyonic structure of the deconfinement phase, inaccessible by cooling, could explain the metastability.Received: 14 October 2003, Revised: 27 January 2004, Published online: 8 April 2004