Abstract : The elliptic flow $v_{2}$ of thermal photons at midrapidity in Au+Au collisions at $\sqrt{s_{NN}}=200$GeV is predicted, based on three-dimensional ideal hydrodynamics. Because of the interplay between the asymmetry and the strength of the transverse flow, the thermal photon $v_{2}$ reaches a maximum at $\pt \sim $ 2GeV/$c$ and the $\pt$-integrated $v_{2}$ reaches a maximum at about 50% centrality. The $\pt$-integrated $v_{2}$ is very sensitive to the lower limit of the integral but not sensitive to the upper limit due to the rapid decrease in the spectrum of the transverse momentum.
F.-M. Liu, T. Hirano, Klaus Werner, Y. Zhu. Elliptic flow of thermal photons at midrapidity in Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV. Quark Matter 2009, Mar 2009, Knoxville, United States. ⟨in2p3-00409948⟩