Partonic effects on higher-order anisotropic flows in relativistic heavy-ion collisions

Abstract

Higher-order anisotropic flows ν4 and ν6 of charged hadrons in heavy-ion collisions at the Relativistic Heavy Ion Collider are studied in a multiphase transport model that has previously been used successfully for describing the elliptic flow ν2 of identified hadrons in these collisions. We find that the same parton scattering cross section of about 10 mb used in explaining the measured ν2 of charged hadrons can also reproduce the recent data on their ν4 and ν6 from Au+Au collisions at √s=200A GeV. It is further found that ν4 is a more sensitive probe of the initial partonic dynamics in these collisions than ν2. Moreover, higher-order parton anisotropic flows are non-negligible and satisfy the scaling relation νn,q(pT)∼ν2,qn/2(p T), which leads naturally to the observed similar scaling relation among hadron anisotropic flows when the coalescence model is used to describe hadron production from the partonic matter.