The Bonn meson-exchange model for the nucleon-nucleon interaction

We present a comprehensive field-theoretical meson-exchange model for the nucleon-nucleon (NN) interaction below pion production threshold consisting of all diagrams which we believe to be important. Fictitious terms, which characterized most boson-exchange models of the past, are strictly avoided. In particular, apart from the well-known one-pion and one-omega exchange, our model contains an explicit determination of the 2π-exchange contribution. In this 2π-exchange model we take into account virtual isobar excitation and direct π-π interactions consistent with the empirical information from πN and ππ scattering. In addition, higher-order diagrams involving heavy-meson exchanges are included, especially the combination of π and ρ which proves to be crucial for a quantitative description of the low angular momentum phase shifts of NN scattering. Explicit predictions are given for NN scattering and for the deuteron. The overall description of the data is of excellent quality. The comprehensive character of our model yields a definite prediction of the meson-nucleon (-isobar) vertex parameters (coupling constants and cutoff parameters of the vertex from factors). These result from our quantitative fit to the NN data and may in the future be related to QCD. The model provides a sound basis for addressing several important issues in nuclear physics, such as three-body forces, meson-exchange currents, charge symmetry and independence violations, relativistic effects and effects of the nuclear medium on the NN force in the nuclear many-body problem. We also present a simple parametrization of the model by one-boson-exchange terms (in momentum as well as in coordinate space). This is convenient for practical purposes and may be useful in applications to nuclear structure physics. (orig.)