Form factors for two-nucleon transfer in the diabolical region of rotating nuclei

Abstract

Abstract The theoretical investigation of rotational bands in strongly deformed nuclei by Coulomb excitation and the subsequent transfer of nucleon pairs requires the knowledge of two-nucleon transfer amplitudes between rotating eigenstates of the A and the A ± 2 systems. In a semiclassical approximation these amplitudes are obtained by integrating over transfer form factors depending on the orientation angle of the deformed target nucleus. We use the cranking approximation based on a rotating mean field in order to calculate these transfer form factors. Their behavior is studied as a function of angular momentum, deformation and pairing correlations. In the region of diabolical points these form factors show considerable oscillations and phase changes reflecting the microscopic single-particle structure involved in these matrix elements. In this way we are able to understand the underlying microscopic structure causing the diabolical behavior of pair transfer in this region.