Eur. Phys. J. A (2006) 29: 119-121
https://doi.org/10.1140/epja/i2005-10309-6

Quark-Gluon-Plasma Thermalization

The thermal model and the transition from baryonic to mesonic freeze-out

¹ UCT-CERN Research Centre and Department of Physics, University of Cape Town, 7701, Rondebosch, South Africa
² Darmstadt University of Technology, D-64289, Darmstadt, Germany
³ Institute of Theoretical Physics, University of Wrocław, Pl. Maksa Borna 9, 50-204, Wrocław, Poland
⁴ CERN TH, CH 1211, Geneva 23, Switzerland

^* e-mail: cleymans@qgp.phy.uct.ac.za

Received: 21 October 2005
Accepted: 2 January 2006
Published online: 31 August 2006

Abstract

The present status of the thermal model is reviewed and the recently discovered sharp peak in the K ⁺/π⁺ ratio is discussed in this framework. It is shown that the rapid change is related to a transition from a baryon-dominated hadronic gas to a meson-dominated one. Further experimental tests to clarify the nature of the transition are discussed. In the thermal model the corresponding maxima in the Ξ/π and Ω/π ratios occur at slightly different beam energies.