2018 Impact factor 4.843
Particles and Fields
Eur. Phys. J. C 2, 351-358

Hadron production in relativistic nuclear collisions: thermal hadron source or hadronizing quark-gluon plasma?

C. Spieles1 - H. Stöcker1 - C. Greiner2

1 Institut für Theoretische Physik, J. W. Goethe-Universität, D-60054 Frankfurt am Main, Germany
2 Institut für Theoretische Physik, J. Liebig-Universität, D-35392 Gießen, Germany

Received: 15 April 1997 / Revised version: 5 June 1997

Measured hadron yields from relativistic nuclear collisions can be equally well understood in two physically distinct models, namely a static thermal hadronic source vs. a time-dependent, nonequilibrium hadronization off a quark-gluon plasma droplet. Due to the time-dependent particle evaporation off the hadronic surface in the latter approach the hadron ratios change (by factors of tex2html_wrap_inline468 5) in time. Final particle yields reflect time averages over the actual thermodynamic properties of the system at a certain stage of the evolution. Calculated hadron, strangelet and (anti-)cluster yields as well as freeze-out times are presented for different systems. Due to strangeness distillation the system moves rapidly out of the T, $\mu_q$ plane into the $\mu_s$-sector. Strangeness to baryon ratios fs=1-2 prevail during a considerable fraction (50%) of the time evolution (i.e. $\Lambda$-droplets or even $\Xi^-$-droplets form the system at the late stage: The possibility of observing this time evolution via two-particle correlations is discussed). The observed hadron ratios require $T_c\approx 160$ MeV and B1/4 tex2html_wrap_inline470 200 MeV. If the present model is fit to the extrapolated hadron yields, metastable hypermatter can only be produced with a probability p< 10-8 for $A \ge 4$.

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