Direct photon elliptic flow in Pb–Pb collisions at √sNN=2.76 TeV

Abstract

The elliptic flow of inclusive and direct photons was measured by ALICE for central and semi-central Pb–Pb collisionsat√sNN=2.76 TeV. The photons were reconstructed using the electromagnetic calorimeter PHOS and the centraltracking system. The inclusive photon flow reconstructed with both methods are combined and used to extract thedirect photon flow, using a decay photon simulation and the direct photon excessRγ, in the transverse momentum range 0.9<pT<6.2 GeV/c. We find that the theoretical predictions generally under-predict the results.