A hybrid model approach to the meson and quark theory of nuclear forces and currents

With a particular view to gaining a real understanding of the quark degrees of freedom in nuclei, we propose a simple model for nucleon-nucleon interactions within the framework of the quark cluster theory, which simultaneously incorporates the quark- and gluon-exchange mechanism at short distance and the meson-exchange mechanism at long and intermediate distances. It is shown to reproduce the experimental NN phase shifts and the deuteron properties fairly well. The model is then applied to a study of the electromagnetic properties of the two-baryon system, by putting particular emphasis upon the relation with conventional nuclear theory. The present study shows how the quark degrees of freedom, which should manifest themselves at high momentum transfer, are concealed in the conventional treatment of the two-nucleon problem as long as we observe low momentum transfer phenomena only.