稀土区正常变形奇核-偶核全同带的物理机制  

Underlying Physics of Identical Odd- and Even-Mass Bands in Normally Deformed Rare-Earth Nuclei

作　　者：余雷[1] 刘树新[1] 雷奕安[1] 曾谨言[1] 

机构地区：[1]北京大学物理系

出　　处：《高能物理与核物理》2001年第6期526-532,共7页High Energy Physics and Nuclear Physics

基　　金：国家自然科学基金! ( 1 99750 0 1 );博士点基金!支持项目&&

摘　　要：用处理对力的粒子数守恒方法分析了稀土区正常变形奇核 -偶核全同带的物理机制 .这些全同带的奇粒子均处于推转的低 j高ΩNilsson轨道 .相反 ,建立在高 j闯入轨道上的奇A核转动带的转动惯量 ,无例外都比相邻偶核基态带的转动惯量大得多 .观测到的转动惯量随角频率的变化 (带交叉前 )可以在粒子数守恒的计算中很好地重现 .计算中无自由参数 .单极对力强度与Y2 0 四极对力强度由结合能奇偶差与带首转动惯量奇偶差确定 .The microscopic mechanism of the identical odd and even mass number nuclear bands in normally deformed rare earth nuclei was investigated using the particle number conserving (PNC) method for treating nuclear pairing correlation. It was found that the odd particle of an odd A identical band always occupied a cranked low j and high Ω Nilsson orbital (e.g. proton [404]7/2, [402]5/2). On the contrary, if the odd particle occupies an intruder high j orbital (e.g. neutron [633]7/2, proton [514]9/2), the moment of inertia of the odd A band was much larger than that of neighboring even even ground state band. The observed variation of moment of inertia (below bandcrossing) was reproduced quite well by the PNC calculation, in which no free parameter was involved. The strengths of monopole and Y 20 quadrupole interactions were determined by the experimental odd even differences in binding energy and bandhead moment of inertia.

关 键 词：正常变形 稀土区奇核-偶核全同带 Nilsson轨道 粒子数 守恒方法 转动惯量 单极对力 四极对力 

分 类 号：O571[理学—粒子物理与原子核物理]