HYDRODYNAMICS AND COLLECTIVE BEHAVIOR IN RELATIVISTIC NUCLEAR COLLISIONS

Hydrodynamics is applied to describe the dynamics of relativistic heav y-ion collisions. The focus of the present study is the influence of a possible (phase) transition to the quark-gluon plasma in the nuclear matter equation of state on collective observables, such as the lifeti me of the system and the transverse directed flow of matter. It is sho wn that such a transition leads to a softening of the equation of stat e, and consequently to a time-delayed expansion which is in principle observable via two-particle correlation functions. Moreover, the delay ed expansion leads to a local minimum in the excitation function of tr ansverse directed flow around AGS energies.