THE RELATIVISTIC 2-BODY EQUATION, JACOBI COORDINATES AND RELATIVISTIC WAVE-FUNCTIONS

Starting with a general dispersion relation, the three-dimensional relativistic two-body propagator is expressed in terms of relativistic Jacobi coordinates. This procedure can be used with most of the widely used propagators. The propagator, written in terms of the Jacobi coordinates, is used to define and develop a relativistic two-body wave function. The use of the wave function is illustrated in two cases: photo-disintegration of a system initially consisting of a bound pair, and the calculation of the form factors of such a pair. In each case some minimal three body aspects are present. In each case also the connection between the relativistic wave function that we have defined and the usual nonrelativistic wavefunction based on the Schrodinger equation is clearly (and easily) made.