Schwinger-Dyson Equation, Area Law and Chiral Symmetry in QCD

Abstract

A Schwinger-Dyson equation for the quark propagator is derived in the context of a Bethe-Salpeter second order formalism developped in preceding papers and of the Minimal Area Law model for the evaluation of the Wilson loop. We discuss how the equal time straight line approximation has to be modified to include correctly trajectories going backwards in time. We also show, by an appropriate selection of the solution of the SD equation, that in the limit of zero quark mass chiral symmetry breaking and a zero mass pseudoscalar meson actually occur. The inclusion of backward quark trajectories proves to be essential to make the model consistent with Goldstone's theorem.