Probing the boundaries of the hadronic phase through a strangeness- including statistical bootstrap model

Abstract

A recently constructed strangeness-including statistical bootstrap model (SSBM), which defines the limits of the hadronic phase and provides for a phase beyond, is further extended so as to include a factor ${\ensuremath{\gamma}}_{s}$ that describes strangeness suppression. The model is then used to analyze the multiplicity data from collision experiments in which the colliding entities form isospin symmetric systems, the primary focus being on $S+S$ interactions (NA35 Collaboration). An optimal set of thermodynamical variables is extracted through a fit to both the inclusive $4\ensuremath{\pi}$ and midrapidity data. The assumption that the measured particles originate from a thermally and partial-chemically equilibrated source described by the SSBM is satisfactorily established. The proximity of the thermodynamical variables extracted from the $S+S$ data to the limits of the hadronic phase is systematically investigated. Finally, experimental data from $p+\overline{p}$ collisions (UA5 Collaboration) are similarly analyzed.