Boundary Value Treatment of Nucleon-Nucleon Phase Shifts

The recent phase-shift fits of Feshbach and Lomon to the nucleon-nucleon scattering data in the energy range $0\le E\le 274$ Mev are examined in detail. An attempt is made to improve the agreement with experiment, and the limitations of the Feshbach-Lomon fits are brought out. It is not found possible to obtain agreement with the data at all energies, even if all previously omitted phase shifts for $L\le 3$ are included. An independent fit to the proton-proton data is then developed by a boundary value method similar to that used by Breit and Bouricius, and a set of phase shifts for $L\le 4$ is found which fits the proton-proton cross section and polarization throughout the energy range $0\le E\le 310$ Mev. There seems to be no major obstacle to using the proposed $p-p$ fit as the basis for a charge-independent fit to all the nucleon-nucleon scattering data.