Elliptic flow of charged particles in Pb-Pb collisions at 2.76 TeV

We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at √s_NN=2.76TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (|η|<0.8) and transverse momentum range 0.2<p_t<5.0GeV/c. The elliptic flow signal v₂, measured using the 4-particle correlation method, averaged over transverse momentum and pseudorapidity is 0.087±0.002(stat)±0.003(syst) in the 40%-50% centrality class. The differential elliptic flow v ₂(p_t) reaches a maximum of 0.2 near p_t=3GeV/c. Compared to RHIC Au-Au collisions at √s_NN=200GeV, the elliptic flow increases by about 30%. Some hydrodynamic model predictions which include viscous corrections are in agreement with the observed increase.