Abstract
An experiment focused on the study of shape coexistence and new high-spin structures in has been performed. The nucleus is in a transitional region of the bismuth isotope chain. A large number of new states have been found, resulting in a significant extension of the previously known level scheme. Several new collective structures have been identified. A strongly coupled rotational band built upon the isomeric state was extended up to and an energy of 5706 keV. The member of the band was also found to feed a new long-lived isomeric state with an excitation energy of 2616 keV and a spin and parity of . The half-life of the isomeric state was determined to be . It decays via the emission of 457-keV and 236-keV transitions, respectively. A low-energy 46-keV transition has been identified to depopulate the () isomeric state, with a measured half-life of . This transition allows the excitation energy of the isomeric state to be determined as 2381 keV. The feeding patterns of both and () isomeric states have also been described. This is the first time collective structures have also been observed up to high spins and excitation energies in the neutron-deficient nucleus. Evidence for the manifestation of shape coexistence in is also discussed.
5 More- Received 10 April 2017
DOI:https://doi.org/10.1103/PhysRevC.96.014301
©2017 American Physical Society