论文标题
$ \ sqrt {s _ {\ rm {nn}}} $ = 5.02 TEV使用多相运输模型的PB-PB碰撞中的横向球和方位角各向异性研究
Study of Transverse Spherocity and Azimuthal Anisotropy in Pb-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV using A Multi-Phase Transport Model
论文作者
论文摘要
横向球体是可观察到的事件形状，具有非常独特的能力，可以根据几何形状分离事件。 LHC实验的最新结果表明，横向球体是小型碰撞系统中重要的事件分类器。在这项工作中，我们首次在重离子碰撞中使用横向球体，并对PB-PB碰撞中在$ \ sqrt {s _ {\ rm {\ rm {nn}}} = 5.02 $ tev使用Multi-Phase Transfers Models（Ampt）（Ampt）进行广泛研究。使用2个粒子相关方法估算方位角各向异性，该方法在粒子对的适当假性差距上显着抑制了非流量效应。将AMPT的结果与Pythia8（Angantyr）模型的估计值进行了比较，并且发现随着选定的假性差距，残留的非流量效应变得可忽略不计。我们发现，高球体事件的椭圆流几乎为零，而低球体事件对球形集成事件的椭圆流显着贡献。我们的研究表明，在重离子碰撞中使用横向球，可以增强和/或抑制集体效应。
Transverse spherocity is an event shape observable having a very unique capability to separate the events based on their geometrical shapes. Recent results from experiments at the LHC suggest that transverse spherocity is an important event classifier in small collision systems. In this work, we use transverse spherocity for the first time in heavy-ion collisions and perform an extensive study on azimuthal anisotropy of charged particles produced in Pb-Pb collisions at $\sqrt{s_{\rm{NN}}} = 5.02$ TeV using A Multi-Phase Transport Model (AMPT). The azimuthal anisotropy is estimated using the 2-particle correlation method, which suppresses the non-flow effects significantly with an appropriate pseudorapidity gap of particle pairs. The results from AMPT are compared with estimations from PYTHIA8 (Angantyr) model and it is found that with the chosen pseudorapidity gap the residual non-flow effects become negligible. We found that the high spherocity events have nearly zero elliptic flow while low spherocity events contribute significantly to elliptic flow of spherocity-integrated events. Our studies indicate that using transverse spherocity in heavy-ion collisions, one can enhance and/or suppress the collective effects.
