Beyond mean field study of nuclei in the 132Sn region

Abstract

The region around the doubly magic 132Sn has been the subject of numerous experimental and theoretical studies in the last few years. The reason is that it is of special importance both for nuclear structure as well as nuclear astrophysics. Since the r-process of nucleosynthesis proceeds along the N=82 shell closure there is a close relation between the N=82 shell gap and the A ≈ 130 peak of the solar r-process abundance distribution. Some years ago it had been demonstrated that the assumption of a spherical quenching of the N = 82 neutron shell close to the neutron dripline allows us to properly reproduce the observed abundances. Recently, the unexpected behaviour of the measured 2+ excitation energies in the heavy Cd isotopes 126,128,130Cd have been interpreted as evidence for a weakening of the N = 82 shell closure already one proton pair ‘below’ 132Sn. This study motivated us to perform a detailed beyond mean field study of this region in order to investigate the origin of the observed anomaly of the 2+ energies in the Cd isotopes.