Comparison of heavy-ion transport simulations: Mean-field dynamics in a box
Comparison of heavy-ion transport simulations: Mean-field dynamics in a box
复制标题
重离子输运模拟的比较：盒子中的平均场动力学
DOI：
10.1103/physrevc.104.024603
复制
发表时间：
2021-08-05
影响因子：
3.1
通讯作者：
Zhang, Feng-Shou
中科院分区：
文献类型：
--
作者：
Colonna, Maria;Zhang, Ying-Xun;Zhang, Feng-Shou
在重离子碰撞模拟的输运模型评估项目（TMEP）中，研究了平均场响应。具体来说，零声传播被认为是中子质子对称物质封闭在一个周期性的盒子，在零温度和正常密度。几个运输代码属于两个家庭（BUU-样和QMD-样）的结果进行了比较，彼此之间和精确的计算。对于BUU类代码，采用测试粒子方法，结果取决于测试粒子的数量和分布的配置文件功能，权重集成在空间上的组合。这些参数可以适当地调整，以给出分析零声特征的良好再现。QMD类代码，使用分子动力学方法，其特征在于大阻尼效应，归因于其相空间表示中固有的波动。此外，对于一个给定的核有效相互作用，他们通常会导致较慢的密度振荡，相比BUU类代码。后一个问题在最近的一些QMD码的晶格公式中得到缓解。讨论了这些结果对描述真实的重离子碰撞的意义。
Within the transport model evaluation project (TMEP) of simulations for heavy-ion collisions, the mean-field response is examined here. Specifically, zero-sound propagation is considered for neutron-proton symmetric matter enclosed in a periodic box, at zero temperature and around normal density. The results of several transport codes belonging to two families (BUU-like and QMD-like) are compared among each other and to exact calculations. For BUU-like codes, employing the test particle method, the results depend on the combination of the number of test particles and the spread of the profile functions that weight integration over space. These parameters can be properly adapted to give a good reproduction of the analytical zero-sound features. QMD-like codes, using molecular dynamics methods, are characterized by large damping effects, attributable to the fluctuations inherent in their phase-space representation. Moreover, for a given nuclear effective interaction, they generally lead to slower density oscillations, as compared to BUU-like codes. The latter problem is mitigated in the more recent lattice formulation of some of the QMD codes. The significance of these results for the description of real heavy-ion collisions is discussed.