The nuclear structure input to astrophysics

The impact of low-energy multipole excitations and pygmy resonances on radiative neutron and proton capture reactions cross sections in nuclei close to the β-stability line is investigated. For this purpose, a microscopic theoretical approach based on self-consistent density functional theory and QRPA formalism supplemented by multi-phonon degrees of freedom, is implemented in a statistical reaction model. The advantage of the method is the fully microscopic nuclear structure input which incorporates low-energy multiphonon excitations, pygmy resonances and core polarization effects related to giant resonances in a unified way. Of particular interest are the pygmy resonances which are found important for the description of nuclear reaction rates of the nucleosynthesis. Calculations of the cross sections of the reactions ⁸⁵Kr(n,γ)⁸⁶Kr, ⁸⁷Sr(n,γ)⁸⁸Sr and ⁸⁹Y(p,γ)⁹⁰Zr are discussed in comparison with the experiment. For the cross sections of the reactions ⁸⁹Zr(n,γ)⁹⁰Zr and ⁹¹Mo(n,γ)⁹²Mo theoretical predictions are made.