The isovector imaginary neutron potential: A key ingredient for the r-process nucleosynthesis

The isovector contribution to the imaginary component of the microscopic optical model potential is adjusted on experimental neutron strength function data. Within the Bruckner-Hartree-Fock approximation of Jeukenne-Lejeune-Mahaux, it is shown that experimental data favours a strong isovector component that can have a drastic impact on the radiative neutron capture cross section for neutron-rich nuclei. If confirmed, this result strongly inhibits the resonant capture by exotic nuclei, so that the traditional r-process picture of the fast neutron captures during the nucleosynthesis r-process needs to be revisited in depth. (c) 2007 Elsevier B.V. All rights reserved.