Momentum Anisotropy of Leptons from Two-Photon Processes in Heavy-Ion Collisions

We investigate the azimuthal angular correlation between the lepton transverse momentum b(perpendicular to) and the impact parameter b(perpendicular to) in noncentral heavy-ion collisions, where the leptons are produced through two-photon scattering. Among the Fourier harmonic coefficients, a significant v(4) asymmetry is found for the typical kinematics at RHIC and LHC with a mild dependence on theb(perpendicular to), whereas v(2) is power suppressed by the lepton mass over b(perpendicular to). This unique prediction, if confirmed from the experiments, shall provide crucial information on the production mechanism for the dilepton in two-photon processes.