Flow Phenomena in Pb-Pb Collisions at CMS

Azimuthal angle correlations of charged hadrons were measured in $\sqrt s_{NN}$ = 2.76 TeV Pb+Pb collisions by the CMS experiment. The distributions exhibit anisotropies that are correlated with the event-by-event orientation of the reaction plane. Several methods were employed to extract the strength of the signal: the event-plane, cumulant and Lee-Yang Zeros methods. These methods have different sensitivity to correlations that are not caused by the collective motion in the system (non-flow correlations due to jets, resonance decays, and quantum correlations). The second Fourier coefficient of the charged hadron azimuthal distributions was measured as a function of transverse momentum, pseudorapidity and centrality in a broad kinematic range, as a function of collision centrality. In addition, results on odd Fourier components will be presented and their connection to the hydrodynamic medium will be discussed.