Energy and mass-number dependence of the dissociation temperature in hydrodynamical models

Transverse-momentum distributions of andK have been analyzed within a framework of the hydrodynamical model to obtain the dependence of the collective transverse flow and the dissociation temperatureT_d inpp- and-induced multiparticle production reactions. The main outcomes are the steadily increasing transverse flow and a slowly decreasingT_d as the incident energy increases. This behavior is in excellent agreement with early Landau's estimate. An extension of this to nucleus-nucleus collisions correctly gives account of the very soft component which has been observed in heavyion experiments.