Intermediate State Coupling and the Interpretation of High-Energy Nucleon-Nucleon Scattering

Abstract

The effect on the scattering of protons by protons of the ${}_{}{}^3{}_{}{}^{}P_2^{}{}_{}{}^{}-{}_{}{}^3{}_{}{}^{}F_2^{}{}_{}{}^{}$ coupling due to an intermediate state of the two-nucleon system is investigated. The problem is treated in a scattering matrix formalism, with total angular momentum $j=2\mathrm{}$, orbital angular momentum $L=j\pm 1$, and partial half-width ${\Gamma }_L$. Only the ${}_{}{}^1{}_{}{}^{}S_0^{}{}_{}{}^{}$, ${}_{}{}^1{}_{}{}^{}D_2^{}{}_{}{}^{}$, ${}_{}{}^3{}_{}{}^{}P_0^{}{}_{}{}^{}$, ${}_{}{}^3{}_{}{}^{}P_1^{}{}_{}{}^{}$, ${}_{}{}^3{}_{}{}^{}P_2^{}{}_{}{}^{}-{}_{}{}^3{}_{}{}^{}F_2^{}{}_{}{}^{}$ scattering anomalies are considered. Fits to the experimental data at 240 Mev are studied as typical. For ${}_{}{}^1{}_{}{}^{}K_0^{}{}_{}{}^{}\approx 31°$, ${}_{}{}^1{}_{}{}^{}K_2^{}{}_{}{}^{}>0\mathrm{}$ it is found that the data may be reasonably well represented provided $\frac{({\Gamma }_1+{\Gamma }_3)}{(E_R-E)}\lesssim 0.3$. It has been found possible to fit data on $n-p$ and $p-p$ scattering employing phase shifts agreeing with the hypothesis of charge independence of nuclear forces. Reasonable agreement with experiment is obtained employing either the regular or the inverted order of ${}_{}{}^3{}_{}{}^{}P_{0,1,2}^{}{}_{}{}^{}$ levels.