Covariant Solutions of the Bethe-Salpeter Equation

Abstract

There is a need for covariant solutions of bound state equations in order to construct realistic QCD based models of mesons and baryons. Furthermore, we ideally need to know the structure of these bound states in all kinematical regimes, which makes a direct solution in Minkowski space (without any 3-dimensional reductions) desirable. The Bethe-Salpeter equation (BSE) for bound states in scalar theories is reformulated and solved for arbitrary scattering kernels in terms of a generalized spectral representation directly in Minkowski space (K. Kusaka et al., PRD 51, 7026 '95). This differs from the conventional Euclidean approach, where the BSE can only be solved in ladder approximation after a Wick rotation.

6 pages of LaTeX, uses lprocl.sty and epsfig.sty with 3 figures. Talk presented at the workshop on Quantum Chromodynamics: Collision, Confinement, and Chaos, at the American University of Paris, France, June 1996, to appear in the conference proceedings. Entire manuscript available as a ps file at http://www.physics.adelaide.edu.au/theory/home.html or ftp://adelphi.adelaide.edu.au/pub/theory/ADP-96-26.T225.ps