Radiative neutron captures by neutron-rich nuclei and the r-process nucleosynthesis

The radiative neutron capture by neutron-rich nuclei is estimated with an improved description of the electric giant dipole resonance. In addition, 3 major effects affecting the capture rates by exotic neutron-rich nuclei are studied. These concern the existence of a low-energy E1 pygmy resonance, the overestimate of the statistical predictions for resonance-deficient nuclei and the direct capture mechanism. The total (n,γ) reaction rates including these 3 effects are evaluated for 3100 neutron-rich nuclei and used in parametric r-process calculations to analyze their impact on the r-abundance distribution.