Nuclear Magnetic and Gamow-Teller Transitions

点击翻译按钮获取中文摘要

Study of the nuclear magnetic moments and beta-decay played a very important role in studying nuclear structure and effeetive interactions. Resently a lot of information about magnetic and Gamow-Teller transitions observed in proton and electron scatterings, londitudinal and transverse responses in the quasi-elastic electron scalterings etc. has been obtained. We have studied the effects of core polarization, especially tensor correlations, meson exchange currents, <DELTA>-hole excitations and quark degrees of freedom on the above reactions. In the magnetic and Gamow-teller transitions, it has been known that the transition strengths have been distributed over the high energy excitation regions experimentally. It was, however, very difficult to clarify the mechanism of the distribution theoretically. We have developed the extended modified Rondom Phase Approximation which takes into account the effect of grount state corretlations and exchange currents.We have also studied the spin-isospin response in the quasi-elastic region. Here the continuum RPA theory has been employed. The method how to include the exchange term has been newly developed. We have obtained the results which are different from other calculations in nuclear matter. We have also applied the continuum RPA with exchange terms on the coulomb sum rule in the electron scattering.