Predictions for flow harmonic distributions and flow factorization ratios at RHIC

Data obtained at RHIC can be reproduced by relativistic viscous hydrodynamic simulations by adjusting the viscosity and initial conditions but it is difficult to disentangle these quantities. It is therefore important to find orthogonal observables to constrain the initial conditions separately from the viscosity. New observables have been measured at the LHC and shown to be sensitive to initial conditions and less to medium properties, specifically factorization breaking ratios appears to be promising. Here we consider two models (NeXus and TRENTO) that reproduce these quantities reasonably well at the LHC and then we make predictions for RHIC. While both models lead to similar results for the scaled flow harmonic distributions, they predict very different patterns for the factorization breaking ratios at RHIC.