Universality of Spectator Fragmentation at Relativistic Bombarding Energies
Multi-fragment decays of 129Xe, 197Au and 238U projectiles in collisions with Be, C, Al, Cu, In, Au and U targets at energies between View the MathML source and 1000 MeV have been studied with the ALADIN forward-spectrometer at SIS. By adding an array of 84 SiCsI(Tl) telescopes the solid-angle coverage of the setup was extended to θlab = 16°. This permitted the complete detection of fragments from the projectile-spectator source. The dominant feature of the systematic set of data is the Zbound universality that is obeyed by the fragment multiplicities and correlations. These observables are invariant with respect to the entrance channel if plotted as a function of Zbound, where Zbound is the sum of the atomic numbers Zi of all projectile fragments with Zi ⩾ 2. No significant dependence on the bombarding energy nor on the target mass is observed. The dependence of the fragment multiplicity on the projectile mass follows a linear scaling law. The reasons for and the limits of the observed universality of spectator fragmentation are explored within the realm of the available data and with model studies. It is found that the universal properties should persist up to much higher bombarding energies than explored in this work and that they are consistent with universal features exhibited by the intranuclear cascade and statistical multifragmentation models.
Repository citation: Schüttauf, A.; Kunze, W. D.; Wörner, A.; Begemann-Blaich, M.; Blaich, Th.; Bowman, D. R.; Charity, R. J.; Cosmo, A.; Ferrero, A.; Gelbke, C. K.; Groß, C.; Hsi, W. C.; Hubele, J.; Immé, G.; Iori, I.; Kempter, J.; Kreutz, P.; Kunde, G. J.; Lindenstruth, V.; Lisa, M. A.; Lynch, W. G.; Lynen, U.; Mang, M.; Möhlenkamp, T.; Moroni, A.; Müller, W. F.J.; Neumann, M.; Ocker, B.; Ogilvie, C. A.; Peaslee, Graham F.; Pochodzalla, J.; Raciti, G.; Rosenberger, F.; Rubehn, Th.; Sann, H.; Schwarz, C.; Seidei, W.; and Serfling, V., "Universality of Spectator Fragmentation at Relativistic Bombarding Energies" (1996). Faculty Publications. Paper 1198.
Published in: Nuclear Physics A, Volume 607, Issue 4, September 30, 1996, pages 457-486. Copyright © 1996 Elsevier.