Strangeness data with light projectiles from a hydrodynamical point of view

The usual particle emission scenario used in hydrodynamics presupposes that particles instantaneously stop interacting (freeze-out) once they reach some three-dimensional surface. Another formalism has recently been developed where particle emission occurs continuously during the whole expansion of thermalized matter. Here we compare both mechanisms in a simplified hydrodynamical framework and show that they lead to a drastically different interpretation of data.

Strangeness data with heavy projectiles from a hydrodynamical point of view

We compare the results obtained by using the continuous emission model with data from Ph-Ph collisions. We determine the initial conditions necessary to reproduce the strange particle ratios (experiment WA97) and with the obtained results, we study the dependence on particle mass of the inverse slope parameter T. Some particle spectra are also shown.

SEMICLASSICAL ESTIMATE OF THE COULOMB-EXCITATION OF THE GIANT-DIPOLE RESONANCE IN PB-208

A semiclassical approach to study pure Coulomb excitation of Pb-208 giant dipole isovector resonance is examined. We consider medium energy projectiles and assume the target excitation to be described by a simple Goldhaber-Teller model. It is shown that the main features concerning the angular distribution are obtained in the angular range described by the model and an estimate is made of the pure Coulomb dipole contribution to the measured cross sections.