Monopole order parameter in SU(2) lattice gauge theory

We report the results of numerical calculations for the probability distribution of the values of the monopole creation operator Phi(mon) in the maximal Abelian projection of SU(2) lattice glucodynamics. It turns out that a low temperature in the confinement phase the maximum of the distribution corresponds to a nonzero value of the field Phi(mon). This means that the effective potential has the form of a Higgs potential. Above the phase-transition point the minimum of the potential (the maximum of the distribution of the monopole creation operator) corresponds to a zero value of the monopole field Phi(mon). The results presented are a direct proof of the existence of a condensate of Abelian monopoles in the confinement phase of glucodynamics, and they confirm the hypothesis that the vacuum of glucodynamics is analogous to a dual superconductor. (C) 1996 American Institute of Physics.