Elliptic flow at high transverse momentum in Pb-Pb collisions at   $\sqrt{s_{NN}} = 2.76$ TeV with the ALICE experiment
  An observable that can be used to better constrain the mechanism responsible for the parton energy loss is the elliptic azimuthal event anisotropy, $v_2$. We report on measurements of $v_2$ for inclusive and identified charged particles in Pb-Pb collisions at $\sqrt{s_{NN}} = 2.76$ TeV recorded by the ALICE experiment at the LHC. $v_2$ is presented for a wide range of particle transverse momentum up to $p_T=20$ GeV/c. The particle $v_2$ is finite, positive and approximately constant for $p_T>8$ GeV/c. The proton $v_2$ is higher than that of the pion up to about $p_T=8$ GeV/c. The results are compared to the measurements at lower energy reported by RHIC experiments. 
A. Dobrin (for the ALICE Collaboration)
nucl-ex