N=100附近同中子偶偶核高-K转动带的组态限制计算  

Configuration-constrained calculations of high-K rotational bands in even-even isotones around N=100

作　　者：戴阿灿 许甫荣[1] Acan Dai;Furong Xu(School of Physics, Peking University, Beijing 100871, China)

机构地区：[1]北京大学物理学院

出　　处：《科学通报》2019年第21期2191-2198,共8页Chinese Science Bulletin

基　　金：国家重点研发计划(2018YFA0404401);国家自然科学基金(11835001,11575007)资助

摘　　要：通过基于Skyrme Hartree-Fock(HF)的组态限制推转壳模型方法系统计算了N=100附近同中子原子核的基态带和高-K转动带.采用粒子数守恒(particle-number-conserving,PNC)方法处理对相互作用.计算的基带和边带都很好地描述了实验转动惯量.对160Sm,164Dy,166Er和168Yb同中子核的K^π=6^-转动带,168Er和170Yb的K^π=4^-转动带以及170Er和172Yb的K^π=6^-转动带进行了系统的研究,并对其进行了相应的微观解释.同时,还预言了158Nd和162Gd同中子核的K^π=6^-转动带以及160Nd,162Sm,164Gd和166Dy同中子核的K^π=4^-转动带.深入研究了原子核转动特性,并对将来的实验提供了有用的信息.Nuclear rotational spectroscopy has been extensively investigated in experimental and theoretical studies.In the collective model,a nucleus can be excited in two ways.One is by breaking pairs of nucleons and exciting nucleons to a higher level.An excited state with a higher K-value sometimes has a long lifetime.Usually those states with lifetimes longer than 1 ns are called isomeric state because of forbidden transitions from high K to low K state.The other way is by collective motions,like rotation and vibration.A rotational band built on the multi-particle state is called a sideband.In general,a nucleus can have more than one sideband.Investigations of sidebands can provide rich information about the nucleus structure,like single-particle level,nuclear shape,and electromagnetic transitions and so on.The traditional total Routhian surface method,which is a powerful tool for investigating nuclear rotation,has been successfully used to describe yrast bands.However,it often encounters non-convergence problems when calculating sidebands.To overcome this problem,we recently developed a configuration-constrained cranking Skyrme Hartree-Fock mean-field calculation with pairing treated by the particle-number-conserving(PNC)method for sidebands.The PNC pairing method follows the technique of a"standard"shell model,which diagonalizes the Hamiltonian in a truncated model space and guarantees the conservation of the particle number.The rare-earth(Z=57-71)neutron-rich nuclides are good candidates for investigating the high-K rotational bands.In this mass region,nuclei with N≥90 are known to be well deformed and many high-j orbitals exist near the neutron and proton Fermi surfaces.These orbitals can form various multi-particle configurations and lead to high-K rotational sidebands.We perform configuration-constrained cranking Skyrme Hartree-Fock mean-field calculations with pairing treated using the PNC method for the high-K rotational bands in even-even isotones near N=100.The K^π=6^- rotational bands in160Sm,164Dy,166Er,

关 键 词：组态限制 粒子数守恒 同中子核 高-K转动带 

分 类 号：O571[理学—粒子物理与原子核物理]