188Pb形变和形状共存的研究

用角动量投影壳模型研究了188Pb核素的形状共存. 实验数据经过计算结果的分析,指出188Pb的低能激发态存在着对应于不同内部粒子组态的球形基态、扁椭球和长椭球三种形状的共存;预言了质子h9/2两粒子-两空穴扁椭球带;指出长椭球带是两种多粒子-空穴激发组态的混杂,并导出了混合系数. 由这些系数,可以说明中子i13/2破对引起的顺排对长椭球带的影响是一个渐进过程;并指出了2+态的能量范围在804-880keV.

Study on Deformation and Shape Coexistence for 188 Pb

The deformation and shape coexistence in 188 Pb have been investigated in terms of the Projected Shell Model. Comparing the experimental data with the calculated results, it is shown that three shape configurations of sphere (Z=82 shell closure), oblate (two particle-two hole in proton h9/2 orbital) and prolate (multi-particle-hole) coexist each other in the low-lying excited states and the prolate band exhibits a mixture between two kinds of multi-particle-hole configurations, which means that the neutron i13/2 alignment happens gradually in this case. The mixing is discussed and the mixing coefficients are given. The oblate band structure is predicted and the 2+ prolate state is estimated to be in the energy range of 804-880keV.