Initial fluctuation effect on harmonic flows in high-energy heavy-ion collisions

Within the framework of a multiphase transport model, harmonic flows v(n) (n = 2, 3, and 4) are investigated for Au-Au collisions at v root(s)NN = 200 GeV and Pb-Pb collisions at root(s)NN = 2.76 TeV. The event-by-event geometry fluctuations significantly contribute to harmonic flows. Triangular flow (v(3)) originates from initial triangularity (epsilon(3)) and is developed by partonic interactions. The conversion efficiency (v(n)/epsilon(n)) decreases with the harmonic order and increases with the partonic interaction cross section. A mass ordering in the low-pT region and a constituent quark number scaling in the middle-pT region seem to work roughly for nth harmonic flows at both energies. All features of harmonic flows show similar qualitative behaviors at BNL Relativistic Heavy Ion Collider and CERN Large Hadron Collider energies, which implies that the formed partonic matters are similar at the two energies.