Vortices and monopole distributions in $Z(2) \times SO(3)$ lattice gauge   theory
  We examine the occurance of Z(2) and SO(3) vorticies and monopole distributions in the neighborhood of Wilson loops. We use the Tomboulis formulation, equivalent to the Wilson action, in which the links are invariant under Z(2) transformations and new plaquette variables carry the Z(2) degrees of freedom. This gives new gauge invariant observables to help gain insight into the area law and structure of the flux tube. 
A. Alexandru, R. W. Haymaker