Breakup Conditions of Projectile Spectators from Dynamical Observables

Abstract

Momenta and masses of heavy projectile fragments (Z >= 8), produced in collisions of 197Au with C, Al, Cu and Pb targets at E/A = 600 MeV, were determined with the ALADIN magnetic spectrometer at SIS. An analysis of kinematic correlations between the two and three heaviest projectile fragments in their rest frame was performed. The sensitivity of these correlations to the conditions at breakup was verified within the schematic SOS-model. The data were compared to calculations with statistical multifragmentation models and to classical three-body calculations. Classical trajectory calculations reproduce the dynamical observables. The deduced breakup parameters, however, differ considerably from those assumed in the statistical multifragmentation models which describe the charge correlations. If, on the other hand, the analysis of kinematic and charge correlations is performed for events with two and three heavy fragments produced by statistical multifragmentation codes, a good agreement with the data is found with the exception that the fluctuation widths of the intrinsic fragment energies are significantly underestimated. A new version of the multifragmentation code MCFRAG was therefore used to investigate the potential role of angular momentum at the breakup stage. If a mean angular momentum of 0.75$\hslash$/nucleon is added to the system, the energy fluctuations can be reproduced, but at the same time the charge partitions are modified and deviate from the data. PACS numbers: 25.70.Mn, 25.70.Pq, 25.75.Ld, 25.75.-q

38 pages, RevTeX with 21 included figures; Also available from http://www-kp3.gsi.de/www/kp3/aladin_publications.html

References in corpus (7)

• Universality of Spectator Fragmentation at Relativistic Bombarding Energies
• Breakup Temperature of Target Spectators in Au + Au Collisions at E/A = 1000 MeV
• The multifragmentation of spectator matter
• Fermionic Molecular Dynamics
• The nuclear liquid-gas phase transition within Fermionic Molecular Dynamics
• Quantum Fluctuation Effects on Nuclear Fragment Formation
• Freeze-out Configuration in Multifragmentation

Cited by in corpus (6)

• Isospin dependent multifragmentation of relativistic projectiles
• Fragment Kinetic Energies and Modes of Fragment Formation
• Statistical Multifragmentation of Non-Spherical Expanding Sources in Central Heavy-Ion Collisions
• Breakup Density in Spectator Fragmentation
• Source shape determination with directional fragment-fragment velocity correlations
• Break-up stage restoration in multifragmentation reactions