相对论平均场理论中的张量项对自旋-轨道劈裂的影响  

Effects of Tensor Coupling on Spin-Orbit Splittings in the Relativistic Mean Field Theory

作　　者：吕洪凤[1] 孟杰[1] 

机构地区：[1]北京大学物理学院,北京100871

出　　处：《高能物理与核物理》2006年第5期412-416,共5页High Energy Physics and Nuclear Physics

基　　金：国家重点基础研究发展规划(G2000077407)国家自然科学基金(10447101;10435010;10221003)资助~~

摘　　要：在相对论平均场理论中引入同位旋标量-矢量介子ω张量项,以208Pb为例,研究了张量项对原子核平均势场、介子场、自旋-轨道耦合势、单粒子能级的自旋-轨道劈裂和原子核壳层结构等的影响．结果发现张量项对核子平均势的影响主要表现在原子核的表面．随着张量耦合强度的增加,自旋-轨道耦合势增强,单粒子能级的自旋-轨道劈裂增大,从而导致原子核单粒子能级的壳层结构发生很大变化,传统幻数所对应的主壳消失,新的主壳出现。The effects of iso-scalar w tensor coupling on spin-orbit splittings are studied in the framework of the Relativistic Mean Field theory. Taking ^208spb as an example, the influence of iso-scalar ω tensor coupling on nuclear mean-field potentials, σ-, ω- and ρ-meson fields, spin-orbit potentials, spin-orbit splittings and the single-particle level structure near the Fermi level are presented. It is found that the tensor term mainly changes the nuclear mean-field potential at the surface. A larger tensor coupling term will lead to stronger spin-orbit potential and larger spin-orbit splitting in the single particle level, which will change the single particle level structure, remove the traditional magic numbers and produce new ones.

关 键 词：相对论平均场理论 张量项 自旋-轨道劈裂 壳层结构 

分 类 号：O571.2[理学—粒子物理与原子核物理]