Longitudinal correlation of the triangular flow event plane in a hybrid approach with hadron and parton cascade initial conditions

The longitudinal long-range correlations of the triangular flow event-plane angles are calculated in a Boltzmann + hydrodynamics hybrid approach. The potential to disentangle different energy deposition scenarios is explored by utilizing two different transport approaches for the early nonequilibrium evolution. In the hadronic transport approach the particle production in high-energy heavy ion reactions is mainly governed by string excitation and fragmentation processes which are absent in the parton cascade approach. We find that in both approaches the initial state shows a strong longitudinal correlation of the event-plane angles which is diluted but still persists in the final state momentum space distributions of the produced particles. The observation of this effect is an important prerequisite for the experimental determination of odd harmonics that relies on a rapidity independent event-plane definition.