Neutron-rich In and Cd isotopes close to the doubly magicSn132

Microsecond isomers in the In and Cd isotopes, in the mass range A = 123 to 130, were investigated at the ILL reactor, Grenoble, using the LOHENGRIN mass spectrometer, through thermal-neutron induced fission reactions of Pu targets. The level schemes of the odd-mass 123–129In and new measurements of the µs half-lives of the odd-odd 126–130In are reported. However, the expected 8+ isomers in the even-mass Cd isotopes were not observed. The comparisons between the experimental B(M2) strengths for In and Sn isotopes are discussed. A shell-model study of the heaviest In and Cd nuclei was performed using a realistic interaction derived from the CD-Bonn nucleon-nucleon potential. The calculation predicts values of the half-lives of the first 8+ states in 126,128Cd of ~10 ns, which could explain the nonobservation of µs isomers. Comparison shows that the calculated levels of 130In and 129In are in good agreement with the experimental values while some discrepancies occur for the lighter In isotopes. The collectivity of 126,128Cd is discussed in the framework of the shell model and in comparison with 204Hg