Proton-hole and core-excited states in the semi-magic nucleus 131In82

. The β decay of the N = 83 nucleus 131 Cd has been studied at the RIBF facility at the RIKEN Nishina Center. The main purpose of the study was to identify the position of the 1 p 3 / 2 and 0 f 5 / 2 proton-hole states and the energies of core-excited configurations in the semi-magic nucleus 131 In. From the radiation emitted following the β decay, a level scheme of 131 In was established and the β feeding to each excited state determined. Similarities between the single-particle transitions observed in the β decays of the N = 83 isotones 132 In and 131 Cd are discussed. Finally the excitation energies of several core-excited configurations in 131 In are compared to QRPA and shell-model calculations.