Reference Spectrum Method for the Boundary-Condition Model of Nuclear Forces

The reference spectrum method of Bethe, Brandow, and Petschek for the calculation of the ground-state properties of nuclear matter is applied to the boundary-condition model of Feshbach and Lomon for the two-nucleon interaction. The short-range contribution to the reference $G$ matrix is evaluated analytically, and the formulas needed for evaluation of the outer contribution given. The method is applied to a simple model interaction (boundary condition plus square well acting in $S$ states only) and results compared with those from typical hard-core potentials. The correction terms to the reference approximation are found to be about one MeV per particle. The important region of intermediate state momenta in which the reference spectrum should be fitted, is again found to be near 4 ${\mathrm{F}}^{-1\mathrm{}}$.