Theoretical Study of Projectile Fragmentations in Relativistic Heavy-Ion Reactions

¹ Department of Physics Selcuk University, 42079 Kampus, Konya, Turkey
² Institute for Nuclear Research,Russian Academy of Sciences, RU-117312 Moscow, Russia
³ Frankfurt Institute for Advanced Studies, J. W. Goethe University, D-60438 Frankfurt am Main, Germany, GSI
⁴ Helmholtzzentrum für Schwerionenforschung GmbH, D-64291 Darmstadt, Germany

Published online: 28 May 2015

Abstract

We have investigated and interpreted the production cross sections and isotopic distributions of projectile-like residues in the reactions ¹²⁴Sn + ¹²⁴Sn and ¹¹²Sn + ¹¹²Sn at an incident beam energy of 1 GeV/nucleon measured with the FRS fragment separator at the GSI laboratory. For the interpretation of the data, calculations within the statistical multifragmentation model (SMM) for an ensemble of excited sources were performed with ensemble parameters. The possible modification of symmetry energy parameter, in the multifragmentation region at the low density and hot freeze-out environment, is studied. It is reconfirmed that a significant reduction of the symmetry energy term is found necessary to reproduce experimental results at these conditions. We have also found a decreasing trend of the symmetry energy for large neutron-rich fragments of low excitation energy which is interpreted as a nuclear-structure effect.