^(134)Ce核的高自旋态与形状共存(英文)

High Spin States and Shape Coexistence in ^(134)Ce

在中国原子能科学研究院H13串列加速器上,通过重离子核反应122Sn(16O,4n)对A=130缺中子核区的134Ce核的高自旋态进行了研究,建立了134Ce的新的能级纲图,最高自旋态扩展到22.然而实验结果与近期发表的134Ce核的高自旋态结果不同,所谓在134Ce核中存在的磁转动带结构不能被实验证实.对实验结果的分析表明,134Ce核的高自旋态结构呈现出重要的形状共存特性在基带以上的回弯处的10+态起源于两个中子组态,基于此10+态的转动带具有γ≈-60°的扁椭形变;另一个10+同质异能态为yrast陷阱,也起源于两中子组态,为具有γ≈-120°的长椭形状;而由两个signature伙伴带组成的强耦合带,则起源于h11/2与g7/2质子组态,为具有γ≈0°的长椭形变带.

High spin states in 134Ce nucleus have been studied by using the heavy-ion induced reaction 122Sn(16O,4n) carried out at China Institute of Atomic Energy. The early level scheme has been extended with spin up to 22 Plank constant/2π. However, our result is different from that in a recent publication, and the magnetic rotation bands reported there have not been confirmed. Our observed level structures may be interpreted as shape coexistence. The 10+ state at the backbending with h11/2 quasineutron configuration has an oblate deformation with an asymmetry parameter γ approximately equals -60° (Lund convention), and the 10+ isomer is a yrast trap of prolate deformation with γ approximately equals -120°,whereas the other signature partner bands with h11/2 and g7/2 proton configuration probably have a prolate deformation with γ approximately equals 0°.