Constraints on symmetry energy and n/p effective mass splitting with improved quantum molecular dynamics model
Constraints on symmetry energy and n/p effective mass splitting with improved quantum molecular dynamics model
复制标题
改进的量子分子动力学模型对对称能和 n/p 有效质量分裂的约束
DOI：
10.13538/j.1001-8042/nst.2013.05.003
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发表时间：
2013-10
影响因子：
2.8
通讯作者：
ZHANG Yingxun, LI Zhuxia, ZHAO Kai, et. al.
中科院分区：
文献类型：
--
作者：
ZHANG Yingxun, LI Zhuxia, ZHAO Kai, et. al.
发展了一种包含标准Skyrme相互作用的改进的量子分子动力学模型。在新程序的基础上，在改进的量子分子动力学模型中采用了四个常用参数集SLy4、Ski2、SKM*和Gs，并研究了同位旋输运比、中子和质子产额的单倍比和双比等同位旋敏感观测值。同位旋输运比对对称能斜率非常敏感，对核子有效质量分裂不是很敏感。另一方面，不同入射能量下反应产生的高能中子和质子产额比很好地反映了核子有效质量分裂的动量依赖关系。通过与实验数据的比较，我们发现在输运模型中考虑Skyrme型相互作用时，约束L值(对称能密度依赖的斜率)约为46 MeV，并且同位旋扩散数据更倾向于Mn*MP*，但对于深χ2极小值的约束并不强。
A new version of improved quantum molecular dynamics model that includes standard Skyrme interactions has been developed. Based on the new code,four commonly used parameter sets,SLy4,SkI2,SkM*and Gs are adopted in the improved quantum molecular dynamics model and the isospin sensitive observables,namely isospin transport ratios,single and double ratios of the yields of neutrons and protons are investigated. The isospin transport ratios are strongly sensitive to the slope of symmetry energy,and are not very sensitive to the nucleon effective mass splitting. On the other hand,the high energy neutrons and protons yields ratios from reactions at different incident energies provide a good observable to the momentum dependence of nucleon effective mass splitting. By comparing our calculations with the data,we find that the constrained L value(the slope of density dependence of symmetry energy) is about ~46 MeV when the Skyrme type interaction is considered in transport models,and the isospin diffusion data prefer to mn*mp*,but it is not a strong constraint with deep χ2minimum.