Discontinuity of the Wilson string tension in the 4-dimensional lattice pure gauge Potts model

We consider the 4-dimensionalq-state pure gauge Potts model. Forq large enough, we give a new proof of the existence of a unique coupling constant β _t , where a first order phase transition occurs. Moreover we prove the following new results: The string tension is discontinuous at β _t , the Wilson parameter exhibits at β _t a direct transition from an area law decay (quark confinement) to a perimeter law decay (quark deconfinement).