Exact implementation of baryon-number conservation in lattice gauge theory

The canonical ensemble is formulated for lattice gauge theory with heavy quarks in the system. A mean-field analysis of SU(2) gauge theory is carried out within this formulation. The dependence of the Wilson loop on the thermodynamical properties is analyzed in an ${\mathrm{SU}}_{\mathrm{C}}$(2)×${\mathrm{U}}_{\mathrm{B}}$(1) phenomenological model. This analysis can contribute to an understanding of the partial-quenching approximation relating to the vanishing of the imaginary part of the Wilson loop on a lattice with the nonzero chemical potential.