Measurement of the elliptic anisotropy of charged particles produced in PbPb collisions at sqrt[s_{NN}]=2.76 TeV

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.