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arXiv 1807.04538nucl-ex
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用ALICE测量小碰撞系统中已识别强子的椭圆流

Elliptic flow of identified hadrons in small collisional systems measured with ALICE

Vojtěch Pacík

摘要:

最近的观测远程多粒子方位角的相关性在p-Pb和高多重PP碰撞提供了新的见解碰撞动力学,并打开了一个可能性,研究集体效应在这些小系统。本文介绍了ALICE在LHC运行2数据采集期间对包含的带电强子以及在$\sqrt{s_\mathrm{NN}}=5.02$ TeV的p-Pb碰撞中所识别的各种粒子种类的$p_\mathrm{T}$ -微分椭圆流($v_{2}$)系数的新测量结果。除了$\mathrm{π^\pm, K^\pm}$和$\mathrm{p(\bar{p})}$的$v_2(p_\mathrm{T})$的高精度测量外,还显示了$\mathrm{K_{S}^{0}, Λ(\barΛ)}$和$ϕ$的第一个结果。为了消除非流动污染,应用相关粒子之间的伪快度分离以及基于在$\sqrt{s}=13$ TeV的最小偏差pp碰撞的测量的剩余非流动估计的减法。此外,报告的特征质量排序以及$v_{2}$的近似NCQ和$\mathrm{KE_T}$缩放允许测试各种理论模型、约束初始条件并探索小型碰撞系统中集体行为的起源。

英文摘要:

Recent observations of long-range multi-particle azimuthal correlations in p--Pb and high multiplicity pp collisions provided new insights into collision dynamics and opened a possibility to study collective effects in these small systems. New measurement of $p_\mathrm{T}$-differential elliptic flow ($v_{2}$) coefficient for inclusive charged hadrons as well as a variety of identified particle species in p--Pb collisions at $\sqrt{s_\mathrm{NN}}=5.02$ TeV recorded by ALICE during the LHC Run 2 data taking are presented. Besides high precision measurements of $v_2(p_\mathrm{T})$ for $\mathrm{π^\pm, K^\pm}$ and $\mathrm{p(\bar{p})}$, the very first results for $\mathrm{K_{S}^{0}, Λ(\barΛ)}$ and $ϕ$ are shown. In order to eliminate non-flow contamination, a pseudorapidity separation between correlated particles is applied as well as subtraction of remaining non-flow estimate based on a measurement of minimum-bias pp collisions at $\sqrt{s}=13$ TeV. Moreover, reported characteristic mass ordering and approximate NCQ and $\mathrm{KE_T}$ scaling of $v_{2}$ allows to test various theoretical models, constrain the initial conditions, and probe the origin of collective behavior in small collision systems.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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