RELATIVISTIC COVARIANCE OF QUASI-POTENTIAL EQUATIONS

We argue that many of the relativistic three-dimensional (quasipotenti al) equations used in hadron physics are inconsistent with the discret e symmetries like charge conjugation and CPT, yielding an incorrect Lo rentz structure for the calculated Green's functions. As an exception to this we consider the equal time approximation to the Bethe-Salpeter equation. We also present a covariant quasipotential model for the pi on-nucleon interaction based on hadronic degrees of freedom. (C) 1998 Elsevier Science B.V. All rights reserved.