"Table 36" of "Anisotropic flow and flow fluctuations of identified hadrons in Pb$-$Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV"

The first measurements of elliptic flow of $\mathrm{\pi}^{\pm}$, $\mathrm{K}^{\pm}$, $\mathrm{p}+\bar{\mathrm{p}}$, $\mathrm{K_{S}^{0}}$, $\Lambda+\bar{\Lambda}$, $\mathrm{\phi}$, $\mathrm{\Xi^{\mp}}$, and $\mathrm{\Omega^{\mp}}$ using multiparticle cumulants in Pb--Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV are presented. Results obtained with two- ($v_2\{2\}$) and four-particle cumulants ($v_2\{4\}$) are shown as a function of transverse momentum, $p_{\rm T}$, for various collision centrality intervals. Combining the data for both $v_2\{2\}$ and $v_2\{4\}$ also allows us to report the first measurements of the mean elliptic flow, elliptic flow fluctuations, and relative elliptic flow fluctuations for various hadron species. These observables probe the event-by-event eccentricity fluctuations in the initial state and the contributions from the dynamic evolution of the expanding quark--gluon plasma. The characteristic features observed in previous $p_{\rm T}$-differential anisotropic flow measurements for identified hadrons with two-particle correlations, namely the mass ordering at low $p_{\rm T}$ and the approximate scaling with the number of constituent quarks at intermediate $p_{\rm T}$, are similarly present in the four-particle correlations and the combinations of $v_2\{2\}$ and $v_2\{4\}$. In addition, a particle species dependence of flow fluctuations is observed that could indicate a significant contribution from final state hadronic interactions. The comparison between experimental measurements and CoLBT model calculations, which combine the various physics processes of hydrodynamics, quark coalescence, and jet fragmentation, illustrates their importance over a wide $p_{\rm T}$ range.本研究首次报道了在质心系碰撞能量√s_NN=5.02 TeV的铅-铅（Pb--Pb）碰撞中，利用多粒子累积量（multiparticle cumulants）方法，对π±、K±、p+$ar{p}$、K_S^0、Λ+$ar{Λ}$、φ、Ξ∓以及Ω∓的椭圆流（elliptic flow）开展的测量。基于两粒子累积量（$v_2{2}$）和四粒子累积量（$v_2{4}$）得到的结果，以横向动量（transverse momentum, $p_{ m T}$）为自变量，展示了不同碰撞中心度区间下的椭圆流数值。通过联合分析$v_2{2}$与$v_2{4}$的实验数据，本研究还首次报道了不同强子种类的平均椭圆流、椭圆流涨落及相对椭圆流涨落的测量结果。这些观测量可用于探究初始态的逐事件偏心率涨落，以及膨胀夸克胶子等离子体（quark–gluon plasma）动态演化过程的贡献。此前基于双粒子关联开展的已鉴别强子$p_{ m T}$微分各向异性流测量中所观测到的特征——即低$p_{ m T}$区间的质量分级现象，以及中等$p_{ m T}$区间与组分夸克数近似成比例的标度行为——在四粒子关联分析以及$v_2{2}$与$v_2{4}$的联合分析中同样被观测到。此外，本研究还观测到流涨落存在强子种类依赖性，这一现象暗示末态强子相互作用可能存在显著贡献。将实验测量结果与结合了流体力学、夸克聚结以及喷注碎裂等多种物理过程的CoLBT模型计算结果进行对比，可证明该模型在较宽$p_{ m T}$区间内的适用性与重要性。

搜集汇总

背景与挑战

背景概述

该数据集是ALICE合作组在Pb−Pb碰撞能量√s_NN = 5.02 TeV下，针对Ω∓粒子在中心度40-50%区间测量的各向异性流数据，具体提供了横向动量依赖的v2{2,|Δη|>0.8}值及其误差。这些数据用于研究高能核碰撞中的流涨落和强子相互作用，是理解夸克-胶子等离子体性质的关键实验观测。