Collective flow and two-pion correlations from a relativistic hydrodynamic model with early chemical freeze-out

Abstract

We investigate the effect of early chemical freeze-out on radial flow, elliptic flow, and Hanbury Brown--Twiss (HBT) radii by using a fully three-dimensional hydrodynamic model. When we take account of the early chemical freeze-out, the space-time evolution of temperature in the hadron phase is considerably different from the conventional model in which chemical equilibrium is always assumed. As a result, we find that radial and elliptic flows are suppressed and that the lifetime and the spatial size of the fluid are reduced. We analyze the ${p}_{t}$ spectrum, the differential elliptic flow, and the HBT radii at the Relativistic Heavy-Ion Collider energy by using hydrodynamics with a chemically nonequilibrium equation of state.