arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0907.1165nucl-th
收藏

核对称能的密度依赖性:微观观点

Density dependence of the nuclear symmetry energy: a microscopic perspective

Isaac Vidana, Constanca Providencia, Artur Polls, Arnau Rios

摘要:

我们进行了系统的密度依赖性的核对称性能量的微观Brueckner-Hartree-Fock(BHF)的方法使用现实的阿贡V18核子核子势加上唯象的三体力的Urbana型。我们的结果进行了比较彻底所产生的几个Skyrme和相对论有效的模型。表征同位旋非对称核物质的BHF状态方程的参数值落在这些模型预测的趋势之内,并且与来自重离子碰撞、巨共振或同量异位素模拟态的最新约束是相容的。特别是,我们找到了一个值的斜率参数$L=66.5$兆电子伏,兼容最近的实验约束从同位旋扩散,$L=88 \pm 25$兆电子伏。研究了丰中子同位素的中子皮厚度与对称能的斜率参数$L$和曲率参数$K_{sym}$之间的关系。我们的压边力结果与其他作者用非相对论和相对论有效模型预测的相关性非常一致。分析了这两个参数和中子皮厚度与中子星中非均匀物质向$β$稳定物质跃迁密度的关系。我们的结果证实了中子皮厚度与跃迁密度之间存在着负相关关系。

英文摘要:

We perform a systematic analysis of the density dependence of the nuclear symmetry energy within the microscopic Brueckner--Hartree--Fock (BHF) approach using the realistic Argonne V18 nucleon-nucleon potential plus a phenomenological three body force of Urbana type. Our results are compared thoroughly to those arising from several Skyrme and relativistic effective models. The values of the parameters characterizing the BHF equation of state of isospin asymmetric nuclear matter fall within the trends predicted by those models and are compatible with recent constraints coming from heavy ion collisions, giant monopole resonances or isobaric analog states. In particular we find a value of the slope parameter $L=66.5$ MeV, compatible with recent experimental constraints from isospin diffusion, $L=88 \pm 25$ MeV. The correlation between the neutron skin thickness of neutron-rich isotopes and the slope, $L$, and curvature, $K_{sym}$, parameters of the symmetry energy is studied. Our BHF results are in very good agreement with the correlations already predicted by other authors using non-relativistic and relativistic effective models. The correlations of these two parameters and the neutron skin thickness with the transition density from non-uniform to $β$-stable matter in neutron stars are also analyzed. Our results confirm that there is an inverse correlation between the neutron skin thickness and the transition density.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑