核介质对介子有效质量的影响  

Effects of Nuclear Matter on Messon Masses

作　　者：陈晏军[1] 郭华[1,2] 

机构地区：[1]北京大学技术物理系,教育部重离子物理重点实验室,北京100871 [2]兰州重离子加速器国家实验室原子核理论中心,兰州730000

出　　处：《高能物理与核物理》2004年第4期392-397,共6页High Energy Physics and Nuclear Physics

基　　金：国家自然科学基金 ( 10 2 75 0 0 2 ) ;国家重点基础研究发展规划项目 (G2 0 0 0 0 7740 0 )资助~~

摘　　要：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 .A density dependent relativistic mean field theory is used to investigate the effect of nuclear matter on σ, ω, ρ and π meson masses. The obtained results have been compared with those given by the linear Walecka model, a nonlinear Walecka model with the parameter set TM1, and the TW model. It has been shown that the overall trends predicted by the different models are quite similar. The effective meson masses decrease with the increasing of nuclear matter density in the lower density region, while the effective σ, π meson masses begin to increase with the density of nuclear matter, and the decreasing behaviors for the effective ω, ρ meson masses tend to become slower in the higher density region. The influence of asymmetric parameter α on the effective meson mass is considerably small, moreover, the nonlinear self-interaction terms in the parameter set TM1 and the many-body coupling (σπ) 2 are important to the effective π meson mass.

关 键 词：核介质 有效质量 密度相关 相对论平均场模型 不对称系数 多体耦合项 介子物理 

分 类 号：O572.3[理学—粒子物理与原子核物理]