Proton-hole and core-excited states in the semi-magic nucleus ¹³¹In82
The β decay of the N = 83 nucleus ¹³¹Cd 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 1p₃/₂ and 0 f₅/₂ proton-hole states and the energies of core-excited configurations in the semi-magic nucleus ¹³¹In. From the radiation emitted following the ββ decay, a level scheme of ¹³¹In was established and the β feeding to each excited state determined. Similarities between the single-particle transitions observed in the ββ decays of the N = 83 isotones ¹³²In and ¹³¹Cd are discussed. Finally the excitation energies of several core-excited configurations in ¹³¹In are compared to QRPA and shell-model calculations. ; This work was supported by the Spanish Ministerio de Ciencia e Innovaci´on under contract FPA2011-29854-C04 and the Spanish Ministerio de Econom´ıa y Competitividad under contract FPA2014-57196-C5-4-P, the Generalitat Valenciana (Spain) under grant PROMETEO/2010/101, the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (No. NRF-2014S1A2A2028636), the Priority Centers Research Program in Korea (2009-0093817), OTKA contract number K-100835, JSPS KAKENHI (Grant No. 25247045), the Grant by IN2P3-RFBR under Agreement No. 110291054, the STFC (UK), the European Commission through the Marie Curie Actions call FP7-PEOPLE-2011- IEF under Contract No. 300096, the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02- 06CH11357, the "RIKEN foreign research program" and the German BMBF (No. 05P12RDCIA and 05P12RDNUP) and HIC for FAIR.