双奇核^(136)La的集体带结构  

Collective Band Structures in Doubly Odd ^(136)La Nucleus

作　　者：朱胜江[1] 肖树冬[1] 车兴来[1] 禹英男[1] 李明亮[1] 陈永静[1] 竺礼华[2] 温书贤[2] 吴晓光[2] 李广生[2] 

机构地区：[1]清华大学物理系,北京100084 [2]中国原子能科学研究院,北京102413

出　　处：《高能物理与核物理》2005年第11期1047-1051,共5页High Energy Physics and Nuclear Physics

基　　金：国家重点基础研究发展规划项目(G2000077405);国家自然科学基金(10375032);国家教育部博士点专项基金(20030003090)~~

摘　　要：通过重离子核反应与在束γ谱的实验技术,对A=130缺中子核区的双奇核^(136)La的高自旋态进行了研究,所用核反应为^(130)Te(^(11)B,5n)。实验结果扩展了^(136)La的能级纲图,包括3个集体转动带,最高自旋态达20h。对于πh_(11/2)vh_(11/2)带,观测到了旋称反转与集体回弯现象。通过系统学比较,对旋称反转特性进行了讨论。由推转壳模型的计算指出,此集体回弯是由一对中子的角动量顺排引起的。另外两个集体带为具有γ≈-60°的扁椭形变带,其可能的组态为:πh_(11/2)vg_(7/2)h_(11/2)~2与πg_(7/2)vg_(7/2)~2d_(5/2)h_(11/2)~2。Using heavy-ion nuclear reaction and in-beam T-ray spectroscopy technique, high spin states of ^136La have been studied. The nuclear reaction used is ^130Te（^11B, 5n） with a beam energy 60MeV. The level scheme with three collective band structures has been updated with spin up to 20h. The collective backbending has been observed in πh11/2×vh11/2 band. According to the TRS calculations, this backbending is due to the alignment of a pair of h11/2 neutrons. The signature splitting and inversion for the πh11/2×vh11/2 band were also discussed. Other two bands based on 12^- and 16%＋ levels were proposed as oblate deformation with γ≈ -60°. They most probably originate from fourand six- quasiparticle configurations, that is, πh11/2×vg7/2h^211/2 and πg7/2×vg^27/2d5/2h^211/2 respectively.

关 键 词：核结构 旋称反转 集体回弯 扁椭形变 集体转动带 双奇核 带结构 重离子核反应 实验技术 高自旋态 

分 类 号：O571.21[理学—粒子物理与原子核物理]