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

Starting with a general dispersion relation, the three-dimensional rel ativistic two-body propagator is expressed in terms of relativistic Ja cobi coordinates. This procedure can be used with most of the widely u sed propagators. The propagator, written in terms of the Jacobi coordi nates, is used to define and develop a relativistic two-body wave func tion. The use of the wave function is illustrated in two cases: photo- disintegration of a system initially consisting of a bound pair, and t he calculation of the form factors of such a pair. In each case some m inimal three body aspects are present. In each case also the connectio n between the relativistic wave function that we have defined and the usual nonrelativistic wavefunction based on the Schrodinger equation i s clearly (and easily) made.