Relativistic Hydrodynamics for Heavy--Ion Collisions -- II. Compression of Nuclear Matter and the Phase Transition to the Quark--Gluon Plasma

摘要

We investigate the compression of nuclear matter in relativistichydrodynamics. Nuclear matter is described by a $\sigma-\omega$--type model forthe hadron matter phase and by the MIT bag model for the quark--gluon plasma,with a first order phase transition between both phases. In the presence ofphase transitions, hydrodynamical solutions change qualitatively, for instance,one-dimensional stationary compression is no longer accomplished by a singleshock but via a sequence of shock and compressional simple waves. We constructthe analytical solution to the ``slab-on-slab'' collision problem over a rangeof incident velocities. The performance of numerical algorithms to solverelativistic hydrodynamics is then investigated for this particular test case.Consequences for the early compressional stage in heavy--ion collisions arepointed out.