Date of Original Version




Rights Management

©2013 CERN, for the CMS Collaboration

Abstract or Description

The anisotropy of the azimuthal distributions of charged particles produced in √sNN = 2.76 TeV PbPb collisions is studied with the CMS experiment at the LHC. The elliptic anisotropy parameter, v2, 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 (pT), pseudorapidity (η) over a broad kinematic range, 0.3 < pT < 20 GeV/c, |η| < 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.


Creative Commons

This work is licensed under a Creative Commons Attribution 3.0 License.

Included in

Physics Commons



Published In

Physical Review C, 87, 014902.