From constituent quarks to hadrons in course of nuclear matter expansion

Abstract

The up-dated three-phase concept of nuclear matter evolution in course of cooling down - from the phase of quark-qluon plasma (QGP) through the intermediate phase allowing for massive constituent quarks (valons), pions and kaons (QPK) to the phase of hadronic matter (H) - is exploited for the treatment of relative hadronic yields in the central region of heavy ion collisions. The most attention is paid to the description of the QPK-phase which is argued to be a gaseous one and lasts until the valonic spacing approaches the confinement radius (at the temperature about 110 MeV), when the valons start fusing to be locked, in the end, within the hadrons. The hadronic yields emerged from thermal treatment of QPK-phase and simple combinatorial approach to the hadronization process are shown to fit the available experimental data from AGS, SPS and RHIC quite well. This provides an alternative insight into the real origin of the observed relative hadronic yields which is (to a considerable extent) free of the well known puzzle inherent in some conventional models where the early chemical freeze-out is assumed: namely, why the gaseous thermal approach to actually tightly packed (even overlapping) hadrons seems workable? Many predictions for the other hadronic yields which could be observed at these machines as well as at LHC are given.