Studies of azimuthal dihadron correlations in ultra-central PbPb collisions at=2.76 TeV
Contribuinte(s) |
Universidade Estadual Paulista (UNESP) |
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Data(s) |
03/12/2014
03/12/2014
20/02/2014
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Resumo |
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) 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. |
Formato |
38 |
Identificador |
http://dx.doi.org/10.1007/JHEP02(2014)088 Journal Of High Energy Physics. New York: Springer, n. 2, 38 p., 2014. 1029-8479 http://hdl.handle.net/11449/111339 10.1007/JHEP02(2014)088 WOS:000331974800001 WOS000331974800001.pdf |
Idioma(s) |
eng |
Publicador |
Springer |
Relação |
Journal of High Energy Physics |
Direitos |
openAccess |
Palavras-Chave | #Relativistic heavy ion physics #Heavy Ions #harmonic flow |
Tipo |
info:eu-repo/semantics/article |