Probing the Interior of the Colour Flux Tube

The internal structure of the colour flux tube (CFT) joining a quark pair in the confining phase of any gauge model provides an important test of the dual superconductivity (DS) conjecture , because it should show, as the dual of an Abrikosov vortex, a core of normal, hot vacuum as contrasted with the surrounding medium, which is in the dual superconducting phase. A general way to study the internal structure of the flux tube is to test it with suitable gauge invariant probes. More specifically, the vacuum state of a lattice gauge model is modified by the insertion in the action of a quark source (for instance a Wilson loop). In this modified vacuum (called W-vacuum) one can evaluate the expectation value of various probes as a function of their position with respect the quark sources. Some general results of such an analysis has been already reported in Ref.2. Here I will describe some new results which are specific of the 3D ZZ2 gauge model.