The Nuclear Three Body Problem with Phase Equivalent Separable Interactions

The triton ground state energy and the neutron–deuteron doublet scattering length have been calculated with two families of phase equivalent separable interactions in the 1S0 and 3S1–3D1 states of the nucleon–nucleon interaction. Generating the interactions from a solution of the inverse scattering problem, a separable representation of the nucleon–nucleon interaction is fully exploited to fit the scattering and bound state data as well as possible. Off shell constraints on the interactions are then discussed. Results for the three nucleon quantities are compared to those obtained with realistic local and one boson exchange potentials. It is shown that all results for potentials obeying the known off shell constraints lie on the Phillips band, which appears to be independent of the potential model employed. This is a consequence of the fact that the triton binding energy and doublet scattering length are only sensitive to the broad detail of the nucleon–nucleon S matrix in the 1S0 and 3S1–3D1 states and to certain global features of the residues at the singlet deuteron and deuteron poles. Relatively large off shell variations in the triton binding energy and doublet scattering length along this Phillips band are possible and the plausibility that the experimental values could be fitted is discussed.