标题： 饱和度和波动热点对超相对论重离子碰撞流观测的影响 显示英文标题

标题： Effects of saturation and fluctuating hotspots for flow observables in ultrarelativistic heavy-ion collisions

摘要： 我们研究了饱和动力学效应对中心快度流可观测量的影响，通过将涨落热点引入高能核碰撞的新型MC-EKRT（蒙特卡罗EKRT）事件生成器中。我们证明饱和效应的强度显著影响了LHC处的流系数 $v_3$ 和 $v_2$ 的比值。向核子中加入热点子结构增强了饱和效应，并改善了与测量数据的一致性。我们展示，与早期基于事件的EKRT模型相比，使用带有热点的MC-EKRT初始状态得到的流系数的碰撞能量依赖性得到了改进。此外，我们给出了LHC处Pb+Pb碰撞中的电荷强子多重分布的结果，并表明MC-EKRT中包含的小jet多重性引起的饱和标度涨落以及热点的存在，对于描述分布中的大多重尾部是必要的。 显示英文摘要

摘要： We investigate the effects of saturation dynamics on midrapidity flow observables by adding fluctuating hotspots into the novel Monte Carlo EKRT (MC-EKRT) event generator for high-energy nuclear collisions. We demonstrate that the intensity of the saturation effects significantly affects the ratio between the flow coefficients $v_3$ and $v_2$ at the LHC. Adding a hotspot substructure to the nucleons enhances the saturation effects and improves the agreement with the measured data. We show that the collision-energy dependence of the flow coefficients obtained using the MC-EKRT initial states with hotspots is improved in comparison with the earlier event-by-event EKRT model. In addition, we present the results for the charged hadron multiplicity distribution in Pb+Pb collisions at the LHC, and show that the minijet-multiplicity originating fluctuations of the saturation scale included in MC-EKRT, as well as the presence of hotspots, are necessary for describing the measured large-multiplicity tail in the distribution.