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arXiv · 0708.4115

Thermal and Chemical Freeze-out in Spectator Fragmentation

W. Trautmann·R. Bassini·M. Begemann-Blaich·A. Ferrero·S. Fritz·S. J. Gaff-Ejakov·C. Gross·G. Imme·I. Iori·U. Kleinevoss
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Abstract

Isotope temperatures from double ratios of hydrogen, helium, lithium, beryllium, and carbon isotopic yields, and excited-state temperatures from yield ratios of particle-unstable resonances in 4He, 5Li, and 8Be, were determined for spectator fragmentation, following collisions of 197Au with targets ranging from C to Au at incident energies of 600 and 1000 MeV per nucleon. A deviation of the isotopic from the excited-state temperatures is observed which coincides with the transition from residue formation to multi-fragment production, suggesting a chemical freeze-out prior to thermal freeze-out in bulk disintegrations.

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W. Trautmann, R. Bassini, M. Begemann-Blaich, A. Ferrero, S. Fritz, S. J. Gaff-Ejakov, C. Gross, G. Imme, I. Iori, U. Kleinevoss. 2007-12-17. Thermal and Chemical Freeze-out in Spectator Fragmentation. https://doi.org/10.1103/physrevc.76.064606

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