Monte Carlo Simulations of the SU(2) Vacuum Structure

Lattice Monte Carlo simulations are performed for the SU(2) Yang Mills gauge theory in the presence of an Abelian background with external sources to obtain information on the effective potential. The goal is to investigate the lowest Landau mode that, in the continuum one-loop effective potential, is the crucial mode for instability. It is shown that also in the lattice formulation this lowest Landau mode plays a very peculiar role, and it is important for the understanding of the vacuum properties.