Influence of differential elastic nucleon-nucleon cross section on stopping and collective flow in heavy-ion collisions at intermediate energies
Influence of differential elastic nucleon-nucleon cross section on stopping and collective flow in heavy-ion collisions at intermediate energies
复制标题
微分弹性核子-核子截面对中能重离子碰撞停止和集体流的影响
DOI：
10.1103/physrevc.94.024608
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发表时间：
2016
影响因子：
3.1
通讯作者：
Zhang Hongfei
中科院分区：
文献类型：
--
作者：
Wang Yongjia;Guo Chenchen;Li Qingfeng;Li Zhuxia;Su Jun;Zhang Hongfei
我们考虑了三种不同的核子-核子 (NN) 弹性微分截面：Cugnon 等人。参数化微分截面[Nucl。仪器。方法物理。研究组。 B 111, 215 (1996)]，由Mao等人提出的自洽相对论Boltzmann-Uehling-Uhlenbeck方程的碰撞项导出的微分截面。 [Z。物理。 A 347, 173 (1994)]，以及最新版本的超相对论量子分子动力学 (UrQMD) 模型中的各向同性微分截面。通过这样做，我们研究了束流能量为 150、250、400 和 800MeV/核子的 Au+Au 碰撞中微分弹性神经网络横截面对各种可观测值（例如，核停止、定向流和椭圆流的速度和横向速度依赖性）的影响。通过与这三个微分截面的计算比较，我们发现核阻止本领以及定向流和椭圆流在一定程度上受到微分截面的影响，并且随着束流能量的增加，微分截面对这些可观测量的影响变得更加明显。中子与氢同位素 (Z = 1) 的椭圆流差 nu(n)(2)-nu(H)(2) 和比值 nu(n)(2)/nu(H)(2) 的影响较弱，这些参数已被用作探测高密度核对称能的敏感观测值。
We considered three different nucleon-nucleon (NN) elastic differential cross sections: the Cugnon et al. parameterized differential cross section [Nucl. Instrum. Methods Phys. Res., Sect. B 111, 215 (1996)], the differential cross section derived from the collision term of the self-consistent relativistic Boltzmann-Uehling-Uhlenbeck equation proposed by Mao et al. [Z. Phys. A 347, 173 (1994)], and the isotropic differential cross section within the newly updated version of the ultrarelativistic quantum molecular dynamics (UrQMD) model. By doing so, we investigated the influence of the differential elastic NN cross section on various observables (e.g., nuclear stopping, both the rapidity and transverse-velocity dependence of the directed and elliptic flows) in Au+Au collisions at beam energies 150, 250, 400, and 800MeV/nucleon. By comparing calculations with those three differential cross sections, we found that the nuclear stopping power and the directed and elliptic flows are affected to some extent by the differential cross sections, and the impact of differential cross section on those observables becomes more visible as the beam energy increases. The effect on the elliptic flow difference nu(n)(2)-nu(H)(2) and ratio nu(n)(2)/nu(H)(2) of neutrons versus hydrogen isotopes (Z = 1), which have been used as sensitive observables for probing nuclear symmetry energy at high densities, is weak.