Abstract
The beta decay of has been re-examined in order to search for transitions to highly excited states of which are predicted by the independent-particle model (IPM) to have large matrix elements. Such a transition is found in the 0.16% beta branch to the 4.39-MeV state of : . This state deexcites through gamma branches of (18±7%) to the 2.79-MeV state of and (82±7)% to the 0.197-MeV state; branches to other states below that at 2.79 MeV are less than 5%. These data make it certain that the 4.39-MeV state is of (assuming that the ground state of is of ). If, as is most likely, the 2.79-MeV state of is of , then is strongly favored for the 4.39-MeV level. An IPM state of enjoying a strong beta decay from is predicted at just this energy. Beta decay to the 2.79-MeV state of has . The decay of the 1.56-MeV state of is also examined and a ground-state branch of (2.4±0.5)% is determined. This transition is expected to be weak by both the IPM and the collective models. The used in this experiment was made by the reaction , and the experimental techniques were exclusively those of NaI spectroscopy, including two-dimensional analysis.
- Received 8 September 1965
DOI:https://doi.org/10.1103/PhysRev.141.966
©1966 American Physical Society