Influence of Hydrodynamic Motion on the Mass Effect in the < P_T > Distribution of High Energy Nuclear Collisions

Contrary to that without considering the hydrodynamic motion, the mass effect in the transverse momentum distribution of high energy nuclear collisions is found not negligible at high temperature after the hydrodynamic motion is considered. So on the occasions for high temperature, such as the formation of quark-gluon-plasma, mass effect must be taken into account.