Shape Co-Existence in the Transitional Nuclide ^(157)yb  

作　　者：徐川 华辉 李湘庆 张双全 许甫荣 石跃 竺礼华 吴晓光 李广生 贺创业 

机构地区：[1]School of Physics and State Key Laboratory of Nuclear Physics and Technology,Peking University [2]China Institute of Atomic Energy

出　　处：《Plasma Science and Technology》2012年第6期510-513,共4页等离子体科学和技术（英文版）

基　　金：supported by Natural Science Foundation of China (Nos. 10775005, 10405001, 10875002, 10735010, 10975007, 10875157, J0730316);the Chinese Major State Basic Research Development Program (No. 2007CB815002)

摘　　要：High-spin states in 157Yb have been populated in the 144Sm（160, 3n）157yb fusion- evaporation reaction at a beam energy of 85 MeV, and two rotational bands have been established for the first time. Within the framework of the triaxial particle-rotor model, the energy spectra and single-particle configurations of 157Yb are investigated. The calculated energy spectra agree well with the experimental data. The newly observed vf7/2 band, and the previously known vi13/2 band in 157Yb, are also discussed by means of Total-Routhian-Surface methods. The structural characters observed in 157Yb provide evidence for the shape coexistence of three distinct shapes： prolate, triaxial and oblate. At higher spins, both the vf7/2 band and the vi13/2 band in 157Yb undergo a shape evolution with sizable alignments occurring.High-spin states in 157Yb have been populated in the 144Sm（160, 3n）157yb fusion- evaporation reaction at a beam energy of 85 MeV, and two rotational bands have been established for the first time. Within the framework of the triaxial particle-rotor model, the energy spectra and single-particle configurations of 157Yb are investigated. The calculated energy spectra agree well with the experimental data. The newly observed vf7/2 band, and the previously known vi13/2 band in 157Yb, are also discussed by means of Total-Routhian-Surface methods. The structural characters observed in 157Yb provide evidence for the shape coexistence of three distinct shapes： prolate, triaxial and oblate. At higher spins, both the vf7/2 band and the vi13/2 band in 157Yb undergo a shape evolution with sizable alignments occurring.

关 键 词：157Yb shape coexistence shape evolution triaxial particle-rotor model Tot al- Rout hi an- Surface 

分 类 号：O571[理学—粒子物理与原子核物理]