Effect of Δ holes on magnetism and Gamow-Teller transition

Recently, the influence of Δ-resonance on magnetic moment and Ml and GT type transition has been variously discussed, and the proof of the existence of Ml and GT type giant resonance and the measurement of the transition intensity have been carried out actively. As the method, the effective operator for Ml and GT type transition in nuclei is calculated by the theory of perturbation according to the conventional methods of coordination mixing and exchange current. As the effective interaction especially among others, the method of taking the very simplified form of Landau-Migdal type and adopting up to high order terms in RPA has been performed. In this paper, in order to study to what extent such method is justified, the meaning of the effective interaction written in the Landau-Migdal type is explained by the simplified model, and comparison is attempted with the treatment by perturbation theory exactly considering the realistic effective interaction and the antisymmetry among nucleons. In the nucleon-hole interaction, the parameter showing the intensity of a repulsive force was about 0.7, and it is the established theory that the preceding phenomenon is not likely to be observed. The effect of the state of Δ holes was examined on real nuclei, the nuclei A = 41 with Ca-40 core and Ca-48. (Kako, I.)