arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1608.05545nucl-ex
收藏

用ALICE探测器研究Pb-Pb碰撞中识别粒子的高次谐波各向异性流

Higher harmonic anisotropic flow of identified particles in Pb-Pb collisions with the ALICE detector

Naghmeh Mohammadi

摘要:

各向异性流在夸克胶子等离子体状态方程的建立中起着至关重要的作用。RHIC和LHC的结果表明,重离子碰撞产生的物质表现为一种近乎完美的流体,反映在较低的剪切粘度与熵密度之比($η/s$)上。在流体动力学计算中,较高的流动谐波对$η/s$的值特别敏感。在这项分析中,我们提出了第一个ALICE结果的$p_{\mathrm{T}}$差分$v_{2}$,$v_{3}$和$v_{4}$的$π^{\pm}$,$\mathrm{K}^{\pm}$,p($\bar p$)从高统计2011年重离子运行。我们研究了这些$v_{n}$系数是如何随0- 1\ %和20- 30\ %中心度范围内的粒子质量和中心度而变化的。这些新的测量旨在区分使用不同初始条件的模型,进一步限制$η/s$的值,并允许从系统的流体动力学演化中解耦晚期强子阶段的影响。

英文摘要:

Anisotropic flow plays a crucial role in establishing the equation of state of the Quark Gluon Plasma. The results at RHIC and LHC have demonstrated that the matter created in heavy-ion collisions behaves as a nearly perfect fluid reflected in the low value of the shear viscosity over entropy density ratio ($η/s$). The higher flow harmonics are particularly sensitive to the value of $η/s$ in hydrodynamic calculations. In this analysis, we present the first ALICE results on the $p_{\mathrm{T}}$ differential $v_{2}$, $v_{3}$ and $v_{4}$ for $π^{\pm}$, $\mathrm{K}^{\pm}$, p($\bar p$) from the high statistics 2011 heavy-ion run. We investigate how these $v_{n}$ coefficients evolve with particle mass and centrality for the 0--1\% and 20--30\% centrality ranges. These new measurements aim at differentiating between models that use different initial conditions, constraining further the value of $η/s$ and allowing to decouple the influence of the late hadronic stage from the hydrodynamic evolution of the system.

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。

↑