Abstract
The decay of the and isomers of the isotope was studied at the GSI on-line mass separator by measuring -delayed protons, rays, proton- and proton- coincidences as well as the -strength distribution. We have observed high-spin (up to ) states in populated by proton emission following the decay of the isomers. The major part of the population is related to the decay of the known isomer whose half-life is . The assignment of the high-spin isomer in with a half-life of has been confirmed. The excitation energy and -decay energy of the isomer were measured to be at least 5.4 and , respectively. At this excitation energy, the isomer is expected to be unbound to direct one-proton, two-proton, or decays. The remarkably long half-life of the isomer with the highest spin and excitation energy ever observed for -decaying nuclei makes a new textbook example of a nuclear high-spin trap. The branching ratios for -delayed proton emission are about 20% and 27% for the decays of the and isomers, respectively. The properties of the experimentally identified levels are discussed in comparison to shell-model predictions.
4 More- Received 4 June 2004
DOI:https://doi.org/10.1103/PhysRevC.70.044311
©2004 American Physical Society