NN and 3N Interactions

This chapter provides a short overview of the Covariant Spectator Theory (CST) and its applications to the study of two- and three-nucleon forces. The basic ideas are illustrated using a simple model where two scalar “nucleons” exchange a scalar meson. Then, the equations needed for the realistic description of NN and 3N scattering and bound states are introduced, and a kernel (or relativistic potential) for use in these equations is chosen. Results recently obtained by adjusting the free parameters in this kernel in order to give high-precision fits to the two-nucleon scattering data are presented. These fits automatically give the correct three-body binding energy without the introduction of any additional forces or parameters. The chapter concludes with a discussion of the implications of these results, and an assessment of our current understanding of two- and three-nucleon forces