物理学报2025，Vol.74Issue(3)：10-18,9.DOI:10.7498/aps.74.20240991
镍同位素链原子核低能四极态的微观研究
Microscopic study on low-energy quadrupole states in Ni isotope chain atomic nuclei
摘要
Abstract
This work mainly investigates the properties of the low-energy quadrupole strength in Ni isotopes,especially the evolution of the pygmy quadrupole states with the increase of neutron number.And the effect of shell evolution on the pygmy resonance is also discussed in detail.Based on the Skyrme Hartree-Fock+Bardeen-Cooper-Schrieffer(HF+BCS)theory and the self-consistent quasiparticle random phase approximation(RPA)method,the evolution in the nickel isotope chain with the increase of neutron number is studied.And in the calculations,three effective Skyrme interactions,namely SGII,SLy5 and SKM*,and a density-dependent zero-range type force are adopted.The properties of the first 2+state in Ni isotopes are studied.A good description on the experimental excited energies of the first 2+states are achieved,and the SGII and SLy5 can well describe the reduced electric transition probabilities for 58-68Ni.It is found that the energy value of the first 2+state for 68Ni and 78Ni are obviously high than those of other nuclei,reflecting the obvious shell effect.In addition to the first 2+states,pygmy quadrupole states between 3 MeV and 5 MeV with relatively large electric transition probabilities are evidently found for 70-76Ni in the isoscalar quadruple strength distribution.The pygmy quadrupole states have the energy values decreasing with the number of neutrons increasing,but their strengths increase gradually.Therefore,they are more sensitive to the change in the shell structure.This is due to the fact that the gradual filling of the neutron level 1g9/2 has a significant effect on the pygmy quadrupole states of 70-76Ni,and it leads to switching from proton-dominated excitations to neutron-dominated ones.The pygmy quadrupole states for 70-76Ni are sensitive to the proton and neutron shell gaps,so they can provide the information about the shell evolution in neutron-rich nuclei.关键词
Skyrme能量密度泛函/矮四极共振态/壳结构Key words
Skyrme energy density functional/pygmy quadrupole resonance/shell structure引用本文复制引用
孙帅,安荣,祁淼,曹李刚,张丰收..镍同位素链原子核低能四极态的微观研究[J].物理学报,2025,74(3):10-18,9.基金项目
国家自然科学基金(批准号:12275025,11975096,12135004,11961141004)和中央高校基本科研业务费专项资金(批准号:2020NTST06)资助的课题. Project supported by the National Natural Science Foundation of China(Grant Nos.12275025,11975096,12135004,11961141004)and the Fundamental Research Fund for the Central Universities,China(Grant No.2020NTST06). （批准号:12275025,11975096,12135004,11961141004）
