NONPERTURBATIVE TREATMENT OF THE N-BODY SYSTEM WITH DYNAMICAL MESONS

The variational approach, used by Feynman in the study of the polaron problem, is generalized to treat a system of N non-relativistic partic les interacting with scalar and vector mesons. After integrating out t he meson fields in the path integral formulation we perform a variatio nal calculation for the effective N-body two-time action to obtain the energy and the mass of the system. The interplay of self energies and exchange terms in attaining binding and saturation is examined. We es timate the size of the particles in the medium and give the mean numbe r of mesons as a function of N.