Quasielastic electron scattering in a derivative coupling model with relativistic random phase approximation

We apply the derivative coupling model with ZM and ZM3 parameters to investigate the longitudinal response function in quasielastic electron scattering in the relativistic random phase approximation. The non-spectral method is chosen to describe the nucleon Green's function in a finite nucleus. Some remarks have been made in conclusion.     

核介质对介子有效质量的影响

在密度相关的相对论平均场近似下,研究了核介质密度对σ,ω,ρ,π介子有效质量的影响并与线性Walecka模型、非线性Walecka模型及TW模型的计算相比较,结果表明不同模型参数下的介子有效质量的变化不会有太大的差别.在低密度区域内,介子有效质量随核物质密度的增大而减小,而在密度较高时,σ,π介子的有效质量随核物质密度的增大而增大,ω,ρ介子的有效质量随核物质密度的增大其减小趋于平缓.不对称系数α对介子有效质量的影响很小.在TM1参数中σ介子的非线性自相互作用项以及多体耦合项(σπ)²对于π介子有效质量的影响是重要的.     

中子星物质中的K介子凝聚

用密度相关的相对论平均场理论计算了中子星物质中的K介子凝聚,结果表明中子星物质发生K介子凝聚的临界密度约为2.75ρ₀.中子星物质URCA过程发生的临界密度在考虑DB核物质中核子自能动量修正时为ρρ0≈3.16,在不考虑DB核物质中核子自能动量修正时为ρρ0≈2.25,并进一步计算了密度相关的相对论平均场理论两种参数形式对中子星物质状态方程的影响.     

Nuclear matter and neutron star properties with the extendedNambu-Jona-Lasinio model

An extended Nambu-Jona-Lasinio(eNJL) model with nucleons as the degrees of freedom is used to investigate properties of nuclear matter and neutron stars(NSs),including the binding energy and symmetry energy of the nuclear matter, the core-crust transition density, and mass-radius relation of NSs. The fourth-order symmetry energy at saturation density is also investigated. When the bulk properties of nuclear matter at saturation density are used to determine the model parameters, the double solutions of parameters are obtained for a given nuclear incompressibility. It is shown that the isovector-vector interaction has a significant influence on the nuclear matter and NS properties, and the sign of isovector-vector coupling constant is critical in the determination of the trend of the symmetry energy and equation of state. The effects of the other model parameters and symmetry energy slope at saturation density are discussed.