It is shown that the internal boundary condition (of the Feshbach-Lomon interaction), which has no effect on the two nucleon wave function, has a large effect on the saturation properties of nuclear matter. The binding energy per particle is altered over a range of approximately 30 MeV. The saturation density can be varied while the binding energy is kept fixed by correlated changes of the spin-spin, tensor, and central parts of the internal boundary condition. In this way the nuclear parameters are fitted without altering the good fit of the Feshbach-Lomon interaction to the two body data. The nuclear matter calculation is performed by matrix inversion of a Bethe-Goldstone equation which has been suitably modified to impose the external and internal boundary conditions. A self-consistent hole spectrum is used. A free particle spectrum is used for most of the results. The effect of a single particle potential of the strength that would cancel three-body cluster contributions is investigated, and found to be of marginal importance for the boundary condition type interaction, and insensitive to the potential strength. Best nuclear matter internal parameters are close to the $S$-state pair superfluidity threshold, implying pairing effects in the nuclear surface and neutron stars.

• Received 14 August 1974

DOI:https://doi.org/10.1103/PhysRevC.10.2584