Elliptic flow from quark coalescence: mass ordering or quark number scaling?

Abstract

We show that either mass ordering or quark number scaling of anisotropic flow can result from quark coalescence, depending on the nature of phase space correlations at hadronization. Quark number scaling signals nonequilibrium dynamics because it can only appear when hydrodynamic correlations break down. However, the scaling does not hold for all nonthermal distributions, and is compatible with covariant transport theory only if remarkable cancellations occur at RHIC.