There are excellent opportunities to produce excited heavy hyper residues in relativistic hadron and peripheral heavy-ion collisions. We investigate the disintegration of such residues into hyper nuclei via evaporation of baryons and light clusters and their fission. Previously these processes were well known for normal nuclei as the decay channels at low excitation energies. We have generalized these models for the case of hyper-matter. In this way we make extension of nuclear reaction studies at low temperature into the strange sector. We demonstrate how the new decay channels can be integrated in the whole disintegration process. Their importance for mass and isotope distributions of produced hyper-fragments is emphasized. New and exotic isotopes obtained within these processes may provide a unique opportunity for investigating hyperon interaction in nuclear matter.Comment: 32 pages, 13 figures, accepted to Phys. Rev.

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We analyze the production cross sections and isotopic distributions of projectilelike residues in the reactions 112 Sn + 112 Sn and 124 Sn + 124 Sn at an incident beam energy of 1 GeV/nucleon measured with the fragment separator at the GSI laboratory. Calculations within the statistical multifragmentation model for an ensemble of excited sources were performed with ensemble parameters determined previously for similar reactions at 600 MeV/nucleon. The obtained good agreement with the experiment establishes the universal properties of the excited spectator systems produced during the dynamical stage of the reaction. It is furthermore confirmed that a significant reduction of the symmetry-energy term at the freeze-out stage of reduced density and high temperature is necessary to reproduce the experimental isotope distributions. A trend of decreasing symmetry energy for large neutron-rich fragments of low excitation energy is interpreted as a nuclear-structure effect.

Theoretical calculations are performed to investigate the angular momentum and Coulomb effects on fragmentation and multifragmentation in peripheral heavy-ion collisions at Fermi energies. Inhomogeneous distributions of hot fragments in the freeze-out volume are taken into account by microcanonical Markov chain calculations within the Statistical Multifragmentation Model (SMM). Including an angular momentum and a long-range Coulomb interaction between projectile and target residues leads to new features in the statistical fragmentation picture. In this case, one can obtain specific correlations of sizes of emitted fragments with their velocities and an emission in the reaction plane. In addition, one may see a significant influence of these effects on the isotope production both in the midrapidity and in the kinematic regions of the projectile/target. The relation of this approach to the simulations of such collisions with dynamical models is also discussed.

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