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

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

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

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

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

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

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

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

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

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