Collective flow and correlation with higher harmonic event planes

Abstract

Abstract Azimuthal event anisotropy and particle correlation have been used to analyze the collectivity of the system created in the high-energy heavy-ion collisions in order to study the properties of Quark Gluon Plasma (QGP). Higher harmonic event anisotropy is recently recognized to carry the information of initial participant geometrical fluctuation because of the finite number of participating nucleons in heavy-ion collisions. The system response after the collective expansion can be observed as higher harmonic event anisotropy, the n-th harmonic order dependence can be used to further constrain the hydro-dynamical properties of the system. The multi-particle azimuthal correlation with respect to the higher harmonic event plane can be used as a tool to understand the origin of the higher harmonic event anisotropy and its relation to the medium response from the jet-quenching as soft-hard interplay. Recent results on the higher harmonic event anisotropy measurements and an attempt of two-particle correlation analysis with respect to the higher harmonic event planes are discussed.