Shape co-existence and structural evolution of the vi_(13/2) band in ^(157)Yb  

作　　者：郑勇 周小红 张玉虎 郭应祥 雷相国 刘忠 刘敏良 罗万居 温书贤 竺礼华 杨春祥 

机构地区：[1]Institute of Modern Physics,Chinese Academy of Sciences,Lanzhou 730000,China [2]China Institute of Atomic Energy,Beijing 102413,China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2003年第2期131-136,共6页中国科学：物理学、力学、天文学（英文版）

基　　金：the National Natural Science Foundation of China(Grant Nos.10005012 and 10025525);the"100 Talent Program"of Chinese Academy of Sciences;the Major State Basic Research Development Program of China(Contract No.G2000077400).

摘　　要：The high-spin states of 157Yb have been studied via the reaction of 144Sm(16O, 3n) at 16O energy of 90 MeV using techniques of in-beam γ-ray spectroscopy. Measurement of γ-γ-t coincidences was performed with 11 BGO(AC)HPGe detectors. Based on the γ-γ coincidence relationships and the measured results of γ-ray anisotropies and DCO ratios, the level scheme for 157Yb was established. The shape co-existence and structural evolution of the Vi13/2 band with increasing angular momentum in 157Yb have been discussed. The systematics of the Vi13/2 bands in the N = 87 odd-A isotones have been compared.The high-spin states of157Yb have been studied via the reaction of144Sm(16O, 3n) at16O energy of 90 MeV using techniques of in-beam γ-ray spectroscopy. Measurement of γ-γ-t coincidences was performed with 11 BGO(AC)HPGe detectors. Based on the γ-γ coincidence relationships and the measured results of γ-ray anisotropies and DCO ratios, the level scheme for157Yb was established. The shape co-existence and structural evolution of thevi13/2 band with increasing angular momentum in157Yb have been discussed. The systematics of thevi13/2 bands in theN=87 odd-A isotones have been compared.

关 键 词：IN-BEAM Γ-RAY spectroscopy  level scheme  structural evolution. 

分 类 号：O571.2[理学—粒子物理与原子核物理]