Studies of azimuthal dihadron correlations in ultra-central PbPb collisions at=2.76 TeV

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	Studies of azimuthal dihadron correlations in ultra-central PbPb collisions at=2.76 TeV
	CMS Collaboration
刊名	JOURNAL OF HIGH ENERGY PHYSICS
	2014
期号	2
关键词	QUARK-GLUON PLASMA TRANSVERSE-MOMENTUM DEPENDENCE ELLIPTIC FLOW ECCENTRICITY FLUCTUATIONS ANGULAR-CORRELATIONS ROOT-S(NN)=2.76 TEV COLLABORATION PERSPECTIVE SPECTRA MATTER
通讯作者	Chatrchyan, S (reprint author), Yerevan Phys Inst, Yerevan 375036, Armenia.
英文摘要	Azimuthal dihadron correlations of charged particles have been measured in PbPb collisions at = 2.76TeV by the CMS collaboration, using data from the 2011 LHC heavy-ion run. The data set includes a sample of ultra-central (0-0.2% centrality) PbPb events collected using a trigger based on total transverse energy in the hadron forward calorimeters and the total multiplicity of pixel clusters in the silicon pixel tracker. A total of about 1.8 million ultra-central events were recorded, corresponding to an integrated luminosity of 120 mu b -aEuro parts per thousand 1. The observed correlations in ultra-central PbPb events are expected to be particularly sensitive to initial-state fluctuations. The single-particle anisotropy Fourier harmonics, from v (2) to v (6), are extracted as a function of particle transverse momentum. At higher transverse momentum, the v (2) harmonic becomes significantly smaller than the higher-order v (n) (n a parts per thousand yenaEuro parts per thousand 3). The p (T)-averaged v (2) and v (3) are found to be equal within 2%, while higher-order v (n) decrease as n increases. The breakdown of factorization of dihadron correlations into single-particle azimuthal anisotropies is observed. This effect is found to be most prominent in the ultra-central PbPb collisions, where the initial-state fluctuations play a dominant role. A comparison of the factorization data to hydrodynamic predictions with event-by-event fluctuating initial conditions is also presented.
学科主题	Physics
类目[WOS]	Physics, Particles & Fields
收录类别	SCI
语种	英语
WOS记录号	WOS:000331974800001
公开日期	2016-02-25
内容类型	期刊论文
源URL	[http://ir.ihep.ac.cn/handle/311005/213667]
专题	高能物理研究所_粒子天体物理中心
作者单位	中国科学院高能物理研究所
推荐引用方式 GB/T 7714	CMS Collaboration. Studies of azimuthal dihadron correlations in ultra-central PbPb collisions at=2.76 TeV[J]. JOURNAL OF HIGH ENERGY PHYSICS,2014(2).
APA	CMS Collaboration.(2014).Studies of azimuthal dihadron correlations in ultra-central PbPb collisions at=2.76 TeV.JOURNAL OF HIGH ENERGY PHYSICS(2).
MLA	CMS Collaboration."Studies of azimuthal dihadron correlations in ultra-central PbPb collisions at=2.76 TeV".JOURNAL OF HIGH ENERGY PHYSICS .2(2014).