  
|
     
|
The European Physical Journal C
ISSN: 1434-6044 (printed version)
ISSN: 1434-6052 (electronic version)
Abstract Volume 2 Issue 2 (1998) pp 351-358
theoretical physics:
Hadron production in relativistic nuclear collisions: thermal hadron source or hadronizing quark-gluon plasma?
C. Spieles (1), H. Stöcker (1), C. Greiner (2)
(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
Abstract. 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 $\lessapprox 5$) 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 $f_s=1-2$ 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 $B^{1/4}\gtrapprox 200$ 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 $A \ge 4$.
Article in PDF-Format
Article in (gzipped) PS-Format
Online publication: April 8, 1998
LINK Helpdesk
© Springer-Verlag Berlin Heidelberg 1998