η-nucleus bound states in nuclei

The binding energies η and widths Γη of η-mesic nuclei are calculated.We parameterize the η self-energy in the nuclear medium as a function of energy and density.We find that the single-particle energies are sensitive to the scattering length,and increase monotonically with the nucleus.The key point for the study of η-nucleus bound states is the η-nuclear optical potential.We study the s-wave interactions of η mesons in a nuclear medium and obtain the optical potential Uη≈ -72 MeV.Comparing our results with the previous results,we find that the ηN scattering length aηN is indeed important to the calculations.With increasing nuclear density the effective mass of the η meson decreases.     

同位旋非对称核物质性质与扩展的BHF方法(Ⅳ)单粒子势与有效质量

在扩展的同位旋相关的Brueckner-Hartree-Fock理论框架内,计算了同位旋非对称核物质中质子与中子的单粒子势和有效质量及其同位旋效应,并详细研究和讨论了基态关联对单粒子势和有效质量及其同位旋依赖的影响.     

单粒子势模型下价核子的密度分布

依据实验事实，利用单粒子势模型，计算了一些核态外层价核子的密度分布.计算给出了价核子在核外部分布的概率和贡献，以此作为晕核态的判断标准.通过研究均方根半径随结合能变化的规律，指出了晕核态存在的条件，尤其是质子晕核态存在的条件.这些对判断和寻找晕核态有现实的指导意义. 关键词： 单粒子势模型 价核子 密度分布 中子晕核态 质子晕核态     

LaF分子结构与基态X1Σ+势能曲线研究

用能量一致相对论有效核芯势和含极化函数 4f2g和弥散函数 1s1p1d的价基组 ,在各种计算水平上计算了LaF分子结构、振动频率和离解能 .根据原子分子反应静力学原理导出LaF分子基态可能的电子状态和离解极限 ,用密度泛函理论中的B3LYP方法计算了基态X1Σ+ 势能曲线 ,拟合得到了Murrell Sorbie解析势能函数及其在平衡位置附近的Dunham展开式 ,由此计算的振转常数和实验光谱数据完全吻合 .得到的解析势能函数可用于计算振转光谱精细跃迁结构和原子分子碰撞反应动力学过程 ,具有重要的实用意义 . The equilibrium geometry, harmonic frequency and dissociation energy of the molecule LaF have been calculated on several kinds of computation levels with energy-consistent relativistic effective core potentials and valence basis sets including polarization functions 4f2g and diffuse functions 1s1p1d. The possible electronic state and its reasonable dissociation limit for the ground state of LaF are determined based on Atomic and Molecular Reaction Statics(AMRS). The potential energy curve scan for...     

LaF分子结构与基态X1Σ+势能曲线研究

用能量一致相对论有效核芯势和含极化函数4f2g和弥散函数1s1p1d的价基组, 在各种计算水平上计算了LaF分子结构、振动频率和离解能. 根据原子分子反应静力学原理导出LaF分子基态可能的电子状态和离解极限, 用密度泛函理论中的B3LYP方法计算了基态X1Σ+势能曲线, 拟合得到了Murrell-Sorbie解析势能函数及其在平衡位置附近的Dunham展开式, 由此计算的振转常数和实验光谱数据完全吻合. 得到的解析势能函数可用于计算振转光谱精细跃迁结构和原子分子碰撞反应动力学过程, 具有重要的实用意义.     

磷化物三元混晶中电子-声子相互作用的维度和体积效应

考虑电子-声子耦合强度因维度而异,导出了描述三维、二维和一维混晶中电子-声子相互作用的哈密顿量。考虑构成三元混晶的两种二元晶体的晶格失配会使混晶体积随元素组分比改变,在推导三维、二维和一维三元混晶中极化子自陷能量和重整化有效质量时计入了离子相对位移与二元晶体原胞体积的关系。结果表明:磷化物三元混晶中极化子自陷能量和重整化有效质量随元素组分的变化关系呈明显的非线性特征,对晶格适配明显、电子-声子耦合较强的材料,体积效应不可忽略。维度越低,非线性特征和体积效应越明显。     

Effect of Tensor Force on the Halo Structure of ^29Ne and ^31Ne

The structure of Ne isotopes has been investigated by using deformed Skyrme-Hartree-Fock （SHF） method and BCS approximation. Especially the effect of tensor force on the halo structure of 29Ne and 31Ne is discussed. To this end, the tensor contributions are considered to the energy density function and the single particle potential in SHF theory. For comparison, four Skyrme interactions are used： SLy5 and SGII without tensor force, and SLy5＋T and SGII＋ T with tensor force. The results indicate that the inclusion of tensor force shows a more pronounced halo structure for 31Ne.     

K and K* Exchange Effects in Lambda Hypernuclei

We study the effects of K and K^＊ exchange between the A hyperon and the nucleon in a A hypernueleus, where the nuclear core is described by a successful relativistic mean-field （RMF） model. In general, K and K^＊ are responsible for strangeness exchange in the one-boson-exchange potential model, which are absent in the RMF calculation. We investigate the contribution of Fock terms derived from K and K^＊ exchange. We use a pseudovector coupling for K exchange, which is found to provide a repulsive potential for the A particle in hypernuclei. Both vector and tensor couplings for K^＊ exchange are taken into account, whose combined effect on the A single-particle energy is found to be small.     

6Li与核弹性散射的微观光学势

从基本的Dirac-Brueckner-Hartree-Fock微观理论出发,得到同时包含实部和虚部的核子-核散射的微观光学势,并利用折叠模型直接获得了核一核散射参数无关的整体微观光学势.考虑到核.核散射去弹过程高级项的贡献和6Li的碎裂效应,在微观光学势的实部和虚部中引入了修正因子NR,N1.系统研究了入射粒子6Li与靶核12C,28Si,40Ca,58Ni,90Zr和208Pb散射的微观光学势,计算中虚部增强因子取N1≈3.0,而实部修正因子NR对于给定的碰撞系统几乎是一个常数.理论很好地再现了所有被研究靶核和入射能量的弹性散射实验数据.参数无关的微观理论对核.核散射,尤其是对不稳定核.核系统反应的描述是有价值的.