Eur. Phys. J. A 12, 421-433 (2001)
Testing Dirac-Brueckner models in collective flow of heavy-ion collisionsT. Gaitanos1, C. Fuchs2, H.H. Wolter1 and A. Faessler2
1 Sektion Physik der Universität München, Am Coulombwall 1, D-85748 Garching, Germany
2 Institut für Theoretische Physik der Universität Tübingen, Auf der Morgenstelle 14, D-72076 Tübingen, Germany
(Received: 8 January 2001 / Revised version: 31 October 2001 Communicated by P. Schuck)
We investigate differential in-plane and out-of-plane flow observables in heavy-ion reactions at intermediate energies from 0.2-2 AGeV within the framework of relativistic BUU transport calculations. The mean field is based on microscopic Dirac-Brueckner-Hartree-Fock (DB) calculations. We apply two different sets of DB predictions, those of ter Haar and Malfliet and more recent ones from the Tübingen group, which are similar in general but differ in details. The latter DB calculations exclude spurious contributions from the negative-energy sector to the mean field which results in a slightly softer equation of state and a less repulsive momentum dependence of the nucleon-nucleus potential at high densities and high momenta. For the application to heavy-ion collisions in both cases non-equilibrium features of the phase space are taken into account on the level of the effective interaction. The systematic comparison to experimental data favours the less repulsive and softer model. Relative to non-relativistic approaches one obtains larger values of the effective nucleon mass. This produces a sufficient amount of repulsion to describe the differential flow data reasonably well.
25.75.-q - Relativistic heavy-ion collisions.
25.75.Ld - Collective flow.
25.70.Mn - Projectile and target fragmentation.
21.65.+f - Nuclear matter.
© Società Italiana di Fisica, Springer-Verlag 2001