标题： LHC上重离子和轻离子碰撞中的 charm 含量的生成与流动力学 显示英文标题

标题： Charmed hadron chemistry and flow in heavy and light ion collisions at the LHC

摘要： 我们研究了LHC能区重离子碰撞中的粲介子和粲重子的产生及其椭圆流。 采用（3+1）维CLVisc流体动力学模型得到了这些高能碰撞产生的夸克胶子等离子体（QGP）的时空演化，利用一种改进的朗之万模型模拟了QGP中的重夸克动力学，该模型包含了弹性与非弹性部分子能量损失过程，并通过一个综合的成核-碎裂模型模拟了重夸克强子化。 使用我们的组合方法，首先计算了铅-铅碰撞中不同中心度下横动量（$p_T$）的粲强子比值（$\Lambda_c/D^0$和$D_s/D^0$）以及它们的椭圆流（$v_2$），能量为$\sqrt{s_{NN}}=5.02$~TeV。 由于奇异性增强和部分子凝聚效应，$D_s/D^0$和$\Lambda_c/D^0$的比值从周边碰撞增加到中心碰撞，而$\Lambda_c/D^0$的这种中心依赖性比$D_s/D^0$更强。 我们进一步预测了在 LHC 能量下较小的 Xe+Xe、Ar+Ar 和 O+O 碰撞中，粲强子化学和$p_T$的中心依赖性以及$v_2$。 在四种碰撞系统中观察到$\Lambda_c/D^0$和$D_s/D^0$比值的强中心度和系统大小依赖性。 至于粲强子流，理解不同碰撞系统中$v_2$的中心度依赖性时，系统大小和碰撞几何都非常重要。 我们的研究为相对论核碰撞中大、小系统中的重夸克演化和强子化提供了重要的参考。 显示英文摘要

摘要： We study the charmed meson and baryon production and elliptic flow in ultra-relativistic nucleus-nucleus collisions at the LHC energies. The space-time evolution of quark-gluon plasma (QGP) produced in these energetic collisions is obtained via the (3+1)-dimensional CLVisc hydrodynamics model, the heavy quark dynamics inside the QGP is simulated using an improved Langevin model that incorporates both elastic and inelastic parton energy loss processes, and the heavy quark hadronization is simulated utilizing a comprehensive coalescence-fragmentation model. Using our combined approach, we first calculate charmed hadron ratios, $\Lambda_c/D^0$ and $D_s/D^0$, as well as their elliptic flow ($v_2$) as a function of transverse momentum ($p_T$) for different centralities in Pb+Pb collisions at $\sqrt{s_{NN}}=5.02$~TeV. Due to strangeness enhancement and parton coalescence effects, $D_s/D^0$ and $\Lambda_c/D^0$ ratios increase from peripheral to central collisions, and such centrality dependence for $\Lambda_c/D^0$ is stronger than $D_s/D^0$. We further predict the $p_T$ and centrality dependences of charmed hadron chemistry and $v_2$ in smaller Xe+Xe, Ar+Ar and O+O collisions at the LHC energies. Strong centrality and system size dependences for $\Lambda_c/D^0$ and $D_s/D^0$ ratios are observed across four collision systems. As for charmed hadron flow, both system size and collision geometry are important to understand the centrality dependence of $v_2$ in different collision systems. Our study provides a significant reference for studying heavy quark evolution and hadronizaiton in large and small systems in relativistic nuclear collisions.