Shape isomerism and spectroscopy of [Formula Presented]
Melerangi A., Appelbe D., Page RD., Boardman HJ., Greenlees PT., Jones P., Joss DT., Julin R., Juutinen S., Kettunen H., Kuusiniemi P., Leino M., Muikku MH., Nieminen P., Pakarinen J., Rahkila P., Simpson J.
High spin states in the [Formula Presented] nucleus were populated by the [Formula Presented] reaction at a beam energy of [Formula Presented]. The emitted prompt [Formula Presented] rays were detected with the Jurosphere [Formula Presented]-ray spectrometer, while the recoiling nuclei were identified using an active stopper at the focal plane of the gas-filled separator RITU. A quasi-rotational band that decays to an isomeric state with a half-life [Formula Presented] and its subsequent [Formula Presented] decay to the ground state of [Formula Presented] have been observed for the first time. Based on the observed decays from this isomeric state, we suggest that the spin of the ground state of [Formula Presented] is [Formula Presented]. In addition, a sequence of transitions that bypass this isomeric state has also been observed. Evidence for shape coexistence is presented. The properties of the observed states are discussed in terms of the systematics of the mercury nuclei in this transitional region. © 2003 The American Physical Society.