Natural solution of the low-lying level structure of i 114 from complementary measurements and new interpretation of the high-spin bands

The complex low-spin structure of the proton-rich I6153114 nucleus has been investigated with the JUROGAM 3 germanium array coupled with the MARA mass separator using the Ni58(Zn64,α3pn) fusion-evaporation reaction. The depopulation of the previously known high-spin bands to low-spin states is firmly established, fixing the excitation energies, spins and parities of the states. The present results combined with fragmentary communications and results published from the decay of separated mass-114 beams measured long time ago at ORNL and GSI, led to the conclusion that the previously known 6 s, 266 keV, I=(7) isomer has to be repositioned at 134 keV and its spin-parity changed to 4+. Three new isomers are identified from intensity imbalance of the populating and depopulating transitions, one at 204 keV with I=6+ and a half-life longer than several nanoseconds, and two at 635 and 966 keV with I=5- and I=7-, respectively, with half-lives of a few nanoseconds. The spins of one high-spin band are changed from odd to even and a new interpretation of the two resulting bands with even spins is proposed based on cranked Nilsson-Strutinsky calculations. From the comparison of the observed low-spin states with shell-model calculations it is suggested that the states of the ground-state cascade are oblate, while the other positive-parity states and the high-spin negative-parity bands are prolate.