Continuum quasiparticle random phase approximation for astrophysical direct neutron capture reaction of neutron-rich nuclei

摘要

We formulate a many-body theory to calculate the cross section of directradiative neutron capture reaction by means of the Hartree-Fock-Bogoliubovmean-field model and the continuum quasiparticle random phase approximation(QRPA). A focus is put on very neutron-rich nuclei and low-energy neutronkinetic energy in the range of O(1 keV) - O(1 MeV), relevant for the rapidneutron-capture process of nucleosynthesis. We begin with the photo-absorptioncross section and the E1 strength function, then, in order to apply thereciprocity theorem, we decompose the cross section into partial cross sectionscorresponding to different channels of one- and two-neutron emission decays ofphoto-excited states. Numerical example is shown for the photo-absorption of$^{142}$Sn and the neutron capture of $^{141}$Sn.