1. Comparison of the isotopic distributions measured in the fragmentation of 136Xe and 124Xe projectiles with the EPAX parameterization
Daniela Henzlova
GSI-Darmstadt, Germany
NSCL-MSU, East Lansing, Michigan

2. Overview of the measured cross sections
more than 1100 production cross sections over 4 orders of magnitude
broad nuclear charge range Z=3(5)-56(55) for 136Xe(124Xe)
extensive database for comparison with up-to-date parameterizations
EPAX2 - based on fragmentation reactions of medium to heavy-mass projectiles in relativistic heavy-ion collisions

3. Isotopic resolution of FRS
136Xe
124Xe
N=Z+k, k=4
136Xe + Pb 1A GeV
Z=50
Z=54
final fragments in broad range unambiguously identified

4. Overview of the isotopic distributions
136Xe+Pb 1 A GeV
124Xe+Pb 1 A GeV

5. Comparison with EPAX – lower Z
124Xe+Pb 1 A GeV
EPAX for 124Xe+Pb
136Xe+Pb 1 A GeV
EPAX for 136Xe+Pb
underestimation of production cross sections of lighter isotopes

6. Comparison with EPAX – higher Z
124Xe+Pb 1 A GeV
EPAX for 124Xe+Pb
136Xe+Pb 1 A GeV
EPAX for 136Xe+Pb
underestimation of cross sections of isotopes on the less n-rich side of the isotopic distributions in case of 136Xe projectile
slightly worse agreement with data from more n-rich projectile

7. Comparison with EPAX2 – available data
J. Friese et al., Nucl. Phys. A 553 (1993) 753c
R. Schneider, PhD thesis, TU München (1996); Zeit. für Phys. A 348 (1994) 241
J. Reinhold et al., Phys. Rev. C 58 (1998) 247
this work
scarce experimental data for n-rich Xe isotope available

8. Comparison with EPAX – mean N-over-Z
124Xe+Pb 1 A GeV
136Xe+Pb 1 A GeV
136Xe
124Xe
EPAX for 136Xe+Pb
EPAX for 124Xe+Pb
higher <N>/Z in the vicinity of the 136Xe projectile
low values of <N>/Z of the residues far from both projectiles

9. Comparison with EPAX – mass distributions
124Xe+Pb 1 A GeV
EPAX for 124Xe+Pb
136Xe+Pb 1 A GeV
EPAX for 136Xe+Pb
mass yields for both systems considerably underestimated

10. Summary
strong underestimation of lighter residues production cross sections independently of system isospin
underestimation of less n-rich isotopes for residues in the vicinity of 136Xe projectile
overall 136Xe data worse reproduced
too strong loss of memory on initial N/Z
underestimation of mass yields for both Xe projectiles
present data may serve to refine the EPAX formulation