Measurement of the elliptic anisotropy of charged particles produced in PbPb collisions at root s(NN)=2.76 TeV


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Chatrchyan S., Khachatryan V., Sirunyan A. M. , Tumasyan A., Adam W., Bergauer T., et al.

PHYSICAL REVIEW C, cilt.87, 2013 (SCI İndekslerine Giren Dergi) identifier identifier

Özet

The anisotropy of the azimuthal distributions of charged particles produced in root s(NN) = 2.76 TeV PbPb collisions is studied with the CMS experiment at the LHC. The elliptic anisotropy parameter, upsilon(2), defined as the second coefficient in a Fourier expansion of the particle invariant yields, is extracted using the event-plane method, two- and four-particle cumulants, and Lee-Yang zeros. The anisotropy is presented as a function of transverse momentum (p(T)), pseudorapidity (eta) over a broad kinematic range, 0.3 < p(T) < 20 GeV/c, vertical bar eta vertical bar < 2.4, and in 12 classes of collision centrality from 0 to 80%. The results are compared to those obtained at lower center-of-mass energies, and various scaling behaviors are examined. When scaled by the geometric eccentricity of the collision zone, the elliptic anisotropy is found to obey a universal scaling with the transverse particle density for different collision systems and center-of-mass energies. DOI: 10.1103/PhysRevC.87.014902