Abstract
We report for the first time the -decay scheme of () to (), with a specific focus on the Gamow-Teller strength along isotones. These results were obtained in an experiment performed at the Radioactive Ion Beam Factory (RIBF), RIKEN, where the parent nuclide, , was produced through the in-flight fission of a beam at 345 MeV per nucleon impinging on a target. Based on data from the high-efficiency -ray spectrometer, EUROBALL-RIKEN Cluster Array (EURICA), we constructed a decay scheme of . The half-life of has been determined to be 350(5) ms. A level at 926 keV has been assigned as a () state based on the value of 4.89(6). This () state, commonly observed in odd-odd nuclei, can be interpreted in terms of the configuration formed by the Gamow-Teller transition between a neutron in the orbital and a proton in the orbital. We observe a sharp contrast to this type of -decay branching to the lower-lying states between and , where we see a large reduction as the number of neutrons increases. This is in contrast to the prediction by large-scale shell model calculations. To investigate this type of the suppression, results of the Nilsson model calculations will be discussed. Along the isotones with , we discuss a characteristic feature of the Gamow-Teller distributions at states with respect to the isospin difference.
- Received 3 April 2017
- Revised 23 May 2017
DOI:https://doi.org/10.1103/PhysRevC.96.014325
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