From the Feynman-Schwinger representation to the non-perturbative relativistic bound state interaction

Abstract

We write the 4-point Green function in QCD in the Feynman-Schwinger representation and show that all the dynamical information are contained in the Wilson loop average. We work out the QED case in order to obtain the usual Bethe-Salpeter kernel. Finally we discuss the QCD case in the non-perturbative regime giving some insight in the nature of the interaction kernel.

Comments: 25 pages, RevTex, 3 figures included, typos corrected, to appear in Phys. Rev. D 56