Effect of nuclear periphery on nucleon transfer in peripheral collisions

摘要

A comparison of experimental heavy residue cross sections from the reactions Kr-86 + Ni-64, Kr-86 + Sn-112.124 with the model of deep-inelastic transfer (DIT) is carried out. A modified expression for nucleon transfer probabilities is used at non-overlapping projectile-target configurations, introducing a dependence on isospin asymmetry at the nuclear periphery. The experimental yields of neutron-rich nuclei close to the projectile are reproduced better and the trend deviating from the bulk isospin equilibration is explained. For the neutron-rich products further from the projectile, originating from hot quasiprojectiles, the statistical multifragmentation model reproduces the mass distributions better than the model of sequential binary decay. In the reaction with proton-rich target Sn-112 the nucleon exchange appears to depend on isospin asymmetry of nuclear periphery only when the surface separation is larger than 0.8 fm due to the stronger Coulomb interaction at more compact di-nuclear configuration. (c) 2005 Elsevier B.V. All rights reserved.