椭圆流的魅力和奇异强子在高多重数的 p+Pb 碰撞 at sqrt[s_{NN}]=8.16TeV。

Elliptic Flow of Charm and Strange Hadrons in High-Multiplicity p+Pb Collisions at sqrt[s_{NN}]=8.16 TeV.

机构信息

Yerevan Physics Institute, Yerevan, Armenia.

Institut für Hochenergiephysik, Wien, Austria.

出版信息

Phys Rev Lett. 2018 Aug 24;121(8):082301. doi: 10.1103/PhysRevLett.121.082301.

DOI:10.1103/PhysRevLett.121.082301

PMID:30192601

Abstract

The elliptic azimuthal anisotropy coefficient (v_{2}) is measured for charm (D^{0}) and strange (K_{S}^{0}, Λ, Ξ^{-}, and Ω^{-}) hadrons, using a data sample of p+Pb collisions collected by the CMS experiment, at a nucleon-nucleon center-of-mass energy of sqrt[s_{NN}]=8.16 TeV. A significant positive v_{2} signal from long-range azimuthal correlations is observed for all particle species in high-multiplicity p+Pb collisions. The measurement represents the first observation of possible long-range collectivity for open heavy flavor hadrons in small systems. The results suggest that charm quarks have a smaller v_{2} than the lighter quarks, probably reflecting a weaker collective behavior. This effect is not seen in the larger PbPb collision system at sqrt[s_{NN}]=5.02 TeV, also presented.

摘要

椭圆方位各向异性系数（v_{2}）被测量为魅力（D^{0}）和奇异（K_{S}^{0}，Λ，Ξ^{-}，和 Ω^{-}）强子，使用 CMS 实验收集的 p+Pb 碰撞的数据集，在质心系能量 sqrt[s_{NN}]=8.16 TeV。在高多重 p+Pb 碰撞中，所有粒子种类都观察到了来自长程方位关联的显著正 v_{2}信号。该测量代表了在小系统中开放重味强子可能存在长程集体行为的首次观察。结果表明，魅力夸克的 v_{2}比轻夸克小，可能反映了较弱的集体行为。这种效应在 sqrt[s_{NN}]=5.02 TeV 的更大 PbPb 碰撞系统中没有出现，也进行了展示。