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Jean Cleymans

Publications and source records attributed to Jean Cleymans.

26 records · Page 2Linked to original sources

Thermal Model Description of Strangeness Enhancement at Mid-Rapidity in Pb--Pb collisions at 158 GeV A/c

The results of the WA97 collaboration for strange particle production at mid-rapidity in Pb--Pb collisions at 158 GeV A/c at CERN display a strong strangeness enhancement with system size at mid-rapidity which is dependent on the strangeness of the particle concerned, and saturates at values of participating nucleons greater than 120. These results are phenomenologically described by the mixed canonical ensemble, with canonical (exact) strangeness conservation involving all strange resonances, and grand canonical conservation of charge and baryon number. A detailed quantitative analysis shows that the data are well described by an equilibrium (gamma_S equivalent to 1) hadron gas.

hep-ph↗

Equation of State of Hadronic matter and Electromagnetic Radiation from Relativisitic Heavy Ion Collisions

We study the radiation of thermal photons and dileptons likely to be produced in relativistic heavy ion collisions. We find that the thermal photon multiplicity scales with the charged pion multiplicity as $dN_{ch}/dy)^α$ with $α\sim 1.2$ for a transversely expanding system, contrary to the general belief of a quadratic dependence. The scaling is shown to be valid, both for real and virtual photons. The coefficient of proportionality at a given energy may help us identify the appropriate equation of state of hot hadronic matter produced in such collisions.

nucl-th↗

Entropy per Baryon in Strong Coupling QCD

The entropy per baryon is studied in the strong coupling large dimension $d$ limit of lattice QCD with staggered fermions. The partition function is calculated for non-zero chemical potential and temperature using the $1/d$ expansion. It is found that the entropy per baryon ratio is almost continuous across the transition from the the quark-gluon to the hadronic phase. The relevance of these results for heavy ion collisions is discussed.

hep-lat↗

Thermal Hadron Production in High Energy Heavy Ion Collisions

We provide a method to test if hadrons produced in high energy heavy ion collisions were emitted at freeze-out from an equilibrium hadron gas. Our considerations are based on an ideal gas at fixed temperature $T_f$, baryon number density $n_B$, and vanishing total strangeness. The constituents of this gas are all hadron resonances up to a mass of 2 GeV; they are taken to decay according to the experimentally observed branching ratios. The ratios of the various resulting hadron production rates are tabulated as functions of $T_f$ and $n_B$. These tables can be used for the equilibration analysis of any heavy ion data; we illustrate this for some specific cases.

hep-ph↗