原子核高－K同质异能态的系统研究

The high-K isomer in rare-earth, A~250 and A~130 mass region will be investigated systematically by cranked shell model (CSM) with paring treated by particle-number conserving method and projected shell model (PSM), the main work include: the structure and properties of high-K isomer and isomer decay. The former will focus on the nuclei far from the stable line, i.e. superheavy nuclei around A~250 and neutron-rich nuclei in rare-earth region. The main physics problems intent to resolve are as following: to obtain a set of Nilsson parameters κ and μ for superheavy nuclei and neutron-rich rare-earth mass region, respevtively, by fit the data of the properties of ground state, low-lying excited state and multi-particle high-K state; the high-order deformation and octuple deformation effects; paring correlations; rotational band and K-mixing. The latter will take 178m2Hf isomer as an example to study the isomer decay. Firstly, the CSM-PNC method will be developed to including angular-momentum-projected technique to study decay of an exited state. Based on the investigation of K-mixing, the developed model will be used to calculate the K-forbidden transition. Meanwhile, the PSM will be used to study the high-K isomer decay, to investigate the microscopic mechanism of the high-K isomer decay.

本项目拟应用推转壳模型（CSM）下处理对力的粒子数守恒（PNC）方法及投影壳模型（PSM）对稀土区、A～250区及A～130区的高－K同质异能态做系统研究，主要包括：高－K同质异能态的结构性质和退激辐射衰变。前者的研究将重点放在对远离β稳定线核素（A～250超重核和稀土区丰中子核）高K同质异能态的研究，关注的重要物理问题有：确定能够描述超重核及稀土区丰中子核基态、低激发态和高—K同质异能态性质的平均场势，即：分别拟合确定针对两个核区的两套Nilsson参数κ和μ；高阶形变β6效应和反射不对称形变β3效应；核的对关联；建立在高—K同质异能态上的转动带以及K混合。后者的研究工作将以178m2Hf为例展开。为研究激发态的衰变，首先发展角动量投影的CSM－PNC模型，在K混合研究基础上计算高－K态的K禁戒跃迁，同时开展PSM对高－K态退激发机制的研究工作，揭示高－K同质异能态退激衰变的微观机制。

本项目应用推转壳模型（CSM）下处理对力的粒子数守恒（PNC）方法对稀土区、A～250区的高－K同质异能态做系统研究。研究将重点放在对远离β稳定线核素（A～250超重核和稀土区丰中子核）高K同质异能态的研究，关注的重要物理问题有：确定能够描述超重核及稀土区丰中子核基态、低激发态和高—K同质异能态性质的平均场势，即：分别拟合确定针对两个核区的两套Nilsson参数κ和μ；高阶形变β6效应和反射不对称形变β3效应；核的对关联；建立在高—K同质异能态上的转动带以及K混合。为研究激发态的衰变，发展了宇称投影的CSM－PNC模型，研究具有反射不对称形状的原子核的单粒子及转动性质。