The effect of early chemical freeze out on hydrodynamic evolution from a full 3D hydrodynamic model

We investigate the effect of early chemical freeze-out on radial and elliptic flow by using a fully three dimensional hydrodynamic model. We find that the time evolution of temperature, the thermal freeze-out temperature dependence of average radial flow and the spatial size of the fluid are different from the results obtained by using a conventional hydrodynamic model in which chemical equilibrium is always assumed. We also analyze the pt spectrum and v2(pt) at the RHIC (Relativistic Heavy Ion Collision) energy and consistently reproduce experimental data by choosing the thermal freeze-out temperature Tth=140 MeV. (author)