It is found that a good fit of the unpolarized and polarized two-nucleon scattering data up to 150 Mev can be obtained by adding a phenomenological short-range attractive spin-orbit potential to the mesontheoretic Gartenhaus potential (which contains both central and tensor terms). It is shown that the deep attractive wells which result for certain states can be modified so as to eliminate all undesirable bound states without hurting the fit with the scattering data (at least up to 150 Mev). The predictions of the combined Gartenhaus—spin-orbit potential are examined at 210 and 300 Mev. While the addition of a spin-orbit potential helps materially at these higher energies, it is likely that a precision fit of the 300-Mev scattering will require additional terms in the two-nucleon interaction (containing higher powers of the nucleon momentum than the first).

• Received 14 October 1957

DOI:https://doi.org/10.1103/PhysRev.109.1229