中国科学院上海应用物理研究所机构知识库

Several mechanisms have been proposed for the signature inversion in the structure of A, 80 odd-odd nuclei, but the theoretical calculations have not been conclusive. In this work, the angular momentum projected shell model (PSM) is applied to the nuclei (80,82) Rb. The results of theoretical calculations about the positive-parity yrast band with configuration pig(9/2) circle times nu g(9/2) and the negative-parity yrast band with configuration pi(P-1/2 or P-3/2 or f(5/2)) circle times nu g(9/2) are compared with experimental data, especially, the mechanism of the signature inversion in the positive-parity yrast band is discussed. The interpretation within the projected shell model shows that the signature inversion displayed in the positive-parity yrast band in these nuclei is a signal of a substantial quadrupole shape change with increasing spin where the nucleus evolves from a prolate shape at low spin through a triaxial shape to an oblate shape at high spin. In addition, we also specify the nuclear shape for these two bands in these two unclei, respectively.