1997/06/16 by M. Gaździcki, Marek Gazdzicki · 23 citations
Physics and Astronomy · #Baryon #Condensed matter physics #High-Energy Particle Collisions Research #Large Hadron Collider #Nuclear physics #Nucleon #Particle physics #Phase transition #Physics #Pion #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #Quark–gluon plasma #Strangeness #Strangeness production #Theoretical and Computational Physics #nucl-th
paper · pdf · doi:10.1088/0954-3899/23/12/012
published in Journal of Physics G Nuclear and Particle Physics 23(12), 1881-1888 (IOP Publishing) · 10 pages
arxiv created 1997/06/16 · openalex publication_date 1997/12/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
A systematic analysis of data on strangeness and pion production in nucleon - nucleon and central nucleus - nucleus collisions is presented. It is shown that at all collision energies the pion/baryon and strangeness/pion ratios indicate saturation with the size of the colliding nuclei. The energy dependence of the saturation level suggests that the transition to the quark - gluon plasma occurs between 15 A GeV c −1 (BNL AGS) and 160 A GeV c −1 (CERN SPS) collision energies. The experimental results interpreted in the framework of a statistical approach show that the effective number of degrees of freedom increases in the course of the phase transition and that the plasma created at CERN SPS energies may have a temperature of about 280 MeV (energy density ≈ 10 GeV fm −3 ). The presence of the phase transition can lead to the non-monotonic collision energy dependence of the strangeness/pion ratio. After an initial increase the ratio should drop to the characteristic value for the quark - gluon plasma. Above the transition region the ratio is expected to be collision energy independent. Experimental studies of central Pb+Pb collisions in the energy range 20 - 160 A GeV c −1 are urgently needed in order to localize the threshold energy, and study the properties of the QCD phase transition.