The Relativized Schrödinger Equation

Abstract

The standard Schrödinger equation describes the behaviour of nonrelativistec particles. Nonrelativistic potential models turned out to give a successful description not only of heavy quarkonia but also of ordinary hadrons. One can say that these models work much better then we would naively expect. Nevertheless the quark-quark systems are relativistic ones so that the calculation of relativistic corrections is one of the important problems of quark bound states. The relativistic character of the quark-quark interaction was studied in papers ([31]–[34]). The main point is that the complete quantum field theory of bound states formulated yet, so that we have differently motivated approaches like Bethe-Salpeter and Breit-Fermi equations and the so-called relativized Schrödinger equation which will be considered in this chapter.