Tensor and Spin-Orbit Forces in Nucleon-Nucleon Scattering

Abstract

In order to investigate effects of a tensor force and to examine the necessity of introducing a spin-orbit force at high energies, N-N scattering at 150 Mev is analyzed. The analysis is made taking into account some characteristic features of the pion-theoretical nuclear forces. It is shown that the experimental data around 150 Mev can be well explained by two matn features of nuclear forces: (1) a strong tensor force in the outer part of the interaction and (2) a hard-core-like repulsive interaction in the inner part. lt should be emphasized that the former feature, which is the most characteristic one of the pion-theoretical nuclear forces, is decisively important at such high energies as well as at low energies. No positive evidences is found for such spin-orbit forces as play an important role around 150 Mev. This conclusion is in conflict with the prediction of very strong spin-orbit forces recently made by Signall and Marshak and by Gammel and Thaler. This point is discussed quite in detail. Especially, it is shown that Signell and Marshak's spin-orbit coupling potential comes from their undue reliance on the inner part of Gartenhaus' potential. (auth) 12O82 Strong resonant interactions between the incident meson andmore » the meson cloud of the nucleon were suggested phenomenologically by Dyson and Takeda as a possible interpretation for the second maximum in The effects of /sup -/-p scattering in the Bev region. The former postulates a resonant state in T n 0, while the T = 1 state resonance is proposed by the latter. This investigation is to determine if such a resonancs could be explained qualitatively from the field theoretical point of view. The conclusion can not be reached from the analysis that the resonance between pions actually occurs in the states of T = 0 and T = 1, but the possibility exists that both the states contribute to the second maximum in The effects of -p interactions. (A.C.)« less