Authors: | Hongfei Xi, T. Odeh, R. Bassini, M. Begemann-Blaich, A.S. Botvina, S. Fritz, S.J. Gaff, C. Groß, G. Immé, I. Iori, U. Kleinevoß, G.J. Kunde, W.D. Kunze, U. Lynen, V. Maddalena, M. Mahi, T. Möhlenkamp, A. Moroni, W.F.J. Müller, C. Nociforo, B. Ocker, F. Petruzzelli, J. Pochodzalla, G. Raciti, G. Riccobene, F.P. Romano, Th. Rubehn, A. Saija, M. Schnittker, A. Schüttauf, C. Schwarz, W. Seidel, V. Serfling, C. Sfienti, W. Trautmann, A. Trzcinski, G. Verde, and A. Wörner |
Published: |
Z. Phys. A359(1997)397
Preprint GSI-97-20, March 1997 Preprint nucl-ex/9703004, 25 Mar 1997 Preprint nucl-ex/9703004, 14 Oct 1997 (revised version) |
Erratum: | Eur. Phys. J. A1(1998)235 (Fig. 3 was misprinted) |
Abstract: |
Breakup temperatures were deduced from double ratios of isotope
yields for target spectators produced in the reaction
197Au + 197Au at 1000 MeV per nucleon. Pairs
of 3,4He and 6,7Li isotopes and pairs of
3,4He and H isotopes (p, d and d, t) yield consistent
temperatures after feeding corrections, based on the quantum
statistical model, are applied. The temperatures rise with
decreasing impact parameter from 4 MeV for peripheral to about 10
MeV for the most central collisions.
The good agreement with the breakup temperatures measured previously
for projectile spectators at an incident energy of 600 MeV per
nucleon confirms the universality established for the spectator
decay at relativistic bombarding energies. The measured temperatures
also agree with the breakup temperatures predicted by the
statistical multifragmentation model. For these calculations a
relation between the initial excitation energy and mass was derived
which gives good simultaneous agreement for the fragment charge
correlations.
The energy spectra of light charged particles, measured at
$\theta_{lab}$ = 150o, exhibit Maxwellian shapes with
inverse slope parameters much higher than the breakup temperatures.
The statistical multifragmentation model, because Coulomb repulsion
and sequential decay processes are included, yields light-particle
spectra with inverse slope parameters higher than the breakup
temperatures but considerably below the measured values. The
systematic behavior of the differences suggests that they are caused
by light-charged-particle emission prior to the final breakup stage.
PACS: 25.70.Mn, 25.70.Pq, 25.75.-q |
Paper: |
Postscript
29 pages with 11 embedded figures (600 kb)
TeX Sources (only KP3 use) |
Figures: |
Fig.
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