放射性核束为核物理和核天体物理提供的新机遇

简要介绍了有关放射性核束的研究状况,特别是它为核物理和核天体物理提供的研究机遇,,以及相对论连续谱Ｈａｒｔｒｅｅ－Ｂｏｇｏｌｉｕｂｏｖ的新进展。     

回弯的简单公式

用吴-曾公式描述基带,用常转动惯量公式描述超带,且引入一个唯象的带间相互作用将两个带混合,即可得到对大多数原子核晕带较为理想的描述,还可重现转动惯量的回弯.对公式中的参数做进一步的分析后,可获得核的基态转动惯量与刚体转动惯量等信息.     

Three-Dimensional Angular Momentum Projected Relativistic Point-Coupling Approach for Low-Lying Excited States in 24Mg

A tull three-dimensional angular momentum projection on top ot a triaxial relativistic mean-fieid calculation is implemented for the first time. The underlying Lagrangian is a point coupling model and pairing correlations are taken into account by a monopole force. This method is applied for the low-lying excited states in ^24Mg. Good agreement with the experimental data is found for the ground state properties. A minimum in the potential energy surface for the 22^＋ state, with β≈ 0.55,7 γ≈ 10^o, is used as the basis to investigate the rotational energy spectrum as well as the corresponding B（E2） transition probabilities as compared to the available data.     

单粒子共振态的实稳定方法研究

基于实稳定方法的基本思想，在坐标空间求解了一维势阱和三维球对称势阱中的单粒子共振态，得到的共振能量、宽度和波函数等与散射相移法以及耦合常数的解析延拓方法的结果一致. 关键词： 共振态 实稳定方法 相移 共振宽度     

Stability of Strutinsky Shell Correction Energy in Relativistic Mean Field Theory

The single-particle spectrum obtained from the relativistic mean field （RMF） theory is used to extract the shell correction energy with the Strutinsky method. Considering the delicate balance between the plateau condition in the Strutinsky smoothing procedure and the convergence for the total binding energy, the proper space sizes used in solving the RMF equations are investigated in detail by taking ^208 Pb as an example. With the proper space sizes, almost the same shell correction energies are obtained by solving the RMF equations either on basis space or in coordinate space.     

中子皮厚度与中子星半径

在相对论平均场理论框架下在拉氏量密度中引入同位旋相关的高阶修正项, 研究了中子皮厚度和中子星半径的关系. 利用有效相互作用PK1得到208Pb的中子皮厚度最小可达0.17 fm, 这与近期Skyrme HF模型得到的结果一致. 随着同位旋相关的高阶修正项系数的变化, 208Pb的中子皮厚度和中子星半径的变化趋势相同. By adding isospin dependent high order correction ferms to existing relativistic mean field models．tlle thickness of neuron．skin in 208Pb and the radius of 1.4 solar mass neutron star are studied．The effecfive interaction PK1 would lead the thickness of neutron-skin to a minimum of 0.17 fm which agrees with the analysis from Skyrme‘HF models． The coupling constants of the isospin dependent high order corection terms tend to change，the thickness of neutron-skin and the radius of neutron stars chan ge simultaneously.     

核物质的对称能与中子皮厚度(英文)

在现有的平均场模型中引入同位旋相关的高阶修正项．研究了核物质对称能的密度依赖性和。^208Pb的中子皮厚度。采用新提出的PK1相互作用以及NL3．S271和Z271相互作用．得到核物质饱和点对称能的范围为29-38MeV以及相应的^208Pb中子皮厚度为0．17—0.28fm．在所有相互作用中，核物质饱和点的对称能与^208Pb的中子皮厚度近似呈线性关系。After adding isospin dependent high order correction terms to existing relativistic mean field models (RMF), the density dependence of symmetry energy and the neutron skin thickness S for 208Pb are studied. Using the new effective interaction PK1, together with NL3, S271 and Z271, a range of 29—38 MeV for the symmetry energy for nuclear matter at saturation point and the corresponding neutron skin thickness S = 0.14—0.28 fm for 208Pb are obtained. For all effective interactions, a linear relation between the symmetry energy at saturation point and the neutron skin thickness for 208Pb is observed.     

原子核反核子谱的自旋对称性

简要介绍原子核反核子谱的自旋对称性。通过分析包含标量势和矢量势的核子及反核子Dirac方程的性质,给出核子谱的赝自旋对称性和反核子谱的自旋对称性的起因。对于反核子双重态,除了它们的能量非常接近以外,它们的波函数也几乎严格地满足自旋对称性所要求的关系。     

基于RMF理论对超重核结构和合成以及滴线外核的研究

总结和回顾了超重核结构和反应研究的历史和现状,利用形变约束的相对论平均场理论系统计算了实验观测到的Z=102—112号元素的能量随形变的变化,得到了这些核素的基态和鞍点性质,利用Strutinsky壳修正方法研究了壳效应对这些核素的影响.利用所得到的结构信息,计算了相应的冷熔合反应的截面,给出了与实验相仿的结果,得到Z=118号元素的合成截面为23pb,比宏观模型的结果小20倍.讨论了相关物理量对反应截面的影响.同时,还给出了相对论连续谱Hartree Bogoliubov(RCHB)理论对滴线外核1800Sn的描述. The studieson structure and reaction for superheavy elements are reviewed. Based on constrained relativistic mean field(CRMF) theory, binding energiesof elements from Z=102 to Z=112, which can be measured experimentally, as a function of deformation arecalculated, and the properties of equilibrium and saddle point of these nuclides are obtained. Using the single particle levels based on CRMF, the shell effects are obtained with Structinsky method. The cross sections of the cold fusion are est...