NATURE OF THE VACUUM INSIDE THE COLOR FLUX TUBE

The interior of the color flux tube joining a quark pair can be probed by evaluating the correlator of pair of Polyakov loops in a vacuum mo dified by another Polyakov pair, in order to check the dual supercondu ctivity conjecture, which predicts a deconfined, hot core. We also poi nt out that at the critical point df any 3D gauge theories with a cont inuous deconfining transition the Svetitsky-Yaffe conjecture provides us with an analytic expression of the Polyakov correlator as a functio n of the location of the probe inside the flux tube. Both these predic tions are compared with numerical results in 3D Z(2) gauge model, find ing complete agreement.