Journal article

Publication year: 2003

Journal: Physical Review C

Volume number: 67

Issue number: 2

ISSN: 0556-2813

eISSN: 1089-490X

Open access status: Green

DOI Link: https://doi.org/10.1103/PhysRevC.67.024903

Publisher: American Physical Society

Abstract: 
Chemical and thermal freeze-out of the hadronic fireball formed in symmetric collisions of light, intermediate-mass, and heavy nuclei at beam energies between 0.8A GeV and 2.0A GeV are discussed in terms of an equilibrated, isospin-symmetric ideal hadron gas with grand-canonical baryon-number conservation. For each collision system the baryochemical potential mu(B) and the chemical freeze-out temperature T-c are deduced from the inclusive pi(0) and eta yields which are augmented by interpolated data on deuteron production. With increasing beam energy mu(B) drops from 800 MeV to 650 MeV, while T-c rises from 55 MeV to 90 MeV. For given beam energy mu(B) grows with system size, whereas T-c remains constant. The centrality dependence of the freeze-out parameters is weak as exemplified by the system Au+Au at 0.8A GeV. For the highest beam energies the fraction of nucleons excited to resonance states reaches freeze-out values of nearly 15%, suggesting resonance densities close to normal nuclear density at maximum compression. In contrast to the particle yields, which convey the status at chemical freeze-out, the shapes of the related transverse-mass spectra do reflect thermal freeze-out. The observed thermal freeze-out temperatures T-th are equal to or slightly lower than T-c, indicative of nearly simultaneous chemical and thermal freeze-out.

Harvard Citation style: Averbeck, R., Holzmann, R., Metag, V. and Simon, R. (2003) Neutral pions and η mesons as probes of the hadronic fireball in nucleus-nucleus collisions around 1A GeV -: art. no. 024903, Physical Review C, 67(2), Article 024903. https://doi.org/10.1103/PhysRevC.67.024903

APA Citation style: Averbeck, R., Holzmann, R., Metag, V., & Simon, R. (2003). Neutral pions and η mesons as probes of the hadronic fireball in nucleus-nucleus collisions around 1A GeV -: art. no. 024903. Physical Review C. 67(2), Article 024903. https://doi.org/10.1103/PhysRevC.67.024903