Octupole degree of freedom for the critical-point candidate nucleus Sm152 in a reflection-asymmetric relativistic mean-field approach
Octupole degree of freedom for the critical-point candidate nucleus Sm152 in a reflection-asymmetric relativistic mean-field approach
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DOI：
10.1103/physrevc.81.034302
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发表时间：
2010-03
影响因子：
3.1
通讯作者：
W. Zhang;Z. Li;S. Zhang;J. Meng
中科院分区：
文献类型：
--
作者：
W. Zhang;Z. Li;S. Zhang;J. Meng
本文采用约束反射非对称相对论平均场方法，以PK 1为参数，研究了偶-偶{sup 146-156}Sm的势能面。结果表明，临界点候选核{sup 152}Sm不仅标志着从U（5）对称到SU（3）对称的形状/相变，而且标志着从{sup 150}Sm的八极形变基态到{sup 154}Sm的四极形变基态的形状/相变。通过引入八极自由度，发现β {sub 2}=0.14approx0.26的{sup 152}Sm单粒子能级在费米面附近存在一个能隙，从而论证了八极形变驱动对nu 2f {sub 7/2}和nu 1 i {sub 13/2}的重要作用.
The potential energy surfaces of even-even {sup 146-156}Sm are investigated in the constrained reflection-asymmetric relativistic mean-field approach with parameter set PK1. It is shown that the critical-point candidate nucleus {sup 152}Sm marks the shape/phase transition not only from U(5) to SU(3) symmetry, but also from the octupole-deformed ground state in {sup 150}Sm to the quadrupole-deformed ground state in {sup 154}Sm. By including the octupole degree of freedom, an energy gap near the Fermi surface for single-particle levels in {sup 152}Sm with beta{sub 2}=0.14approx0.26 is found and the important role of the octupole deformation driving pair nu2f{sub 7/2} and nu1i{sub 13/2} is demonstrated.