1998/06/18 by W. Cassing
Physics and Astronomy · #nucl-th
published as Acta Phys.Polon. B29 (1998) 3175-3183 · 9 pages, LaTeX, including 5 postscript figures and appb.sty; Talk presented at the Workshop on 'The Structure of Mesons, Baryons and Nuclei', Cracow, May 1998, to be published in Acta Physica Polonica B
arxiv created 1998/06/18 · arxiv updated 2009/12/01
The properties of π, η, K+ and K- mesons are studied in nuclear reactions from SIS to SPS energies within the covariant transport approach HSD in comparison to the experimental data. Whereas the pion, η and kaon abundancies and spectra indicate little or vanishing selfe-nergies for these mesons in the medium, antikaons (as well as antiprotons) are found to experience strong attractive potentials in nucleus-nucleus collisions at SIS energies. However, even when including these potentials the K+ and K- spectra at AGS energies are noticeably underestimated showing an experimental excess of strangeness that points towards a nonhadronic phase in these reactions. On the other hand the K+, K- production at SPS energies is well described by the hadronic approach without incorporating any parton degrees of freedom.