The bound-state properties

The trinucleon bound state is the natural testing ground for most of our efforts to determine the effects of three-nucleon forces. The existence of these forces, which depend on the simultaneous coordinates of three nucleons, arises from neglecting non-nucleonic degrees of freedom, such as the excitation of a nucleon in an intermediate state between two exchanges of mesons. Three-body forces are additional forces which may have to be taken into account to explain the binding energies of nuclei for A≥3. In the trinucleon system typical three-nucleon forces change the binding energy by 5-15%, although they generate a much smaller fraction (1-2%) of the total potential energy. This relative smallness has proven to be a serious problem because, until recently, the reliability of calculations was insufficient and there was considerable uncertainty over the accuracy of the wave functions (needed to calculate observables) and eigenvalues. This symposium has shown that considerable progress has recently been achieved. In particular the calculation of the trinucleon bound-state properties due to two-body interactions is now well under control. The different numerical techniques used by various groups show remarkable covergence in the binding energies at a level of accuracy of about 10 keV. (orig./WL)