HIGH-SPIN ROTATIONAL BANDS IN DOUBLY ODD I-118

Three Delta I = 2 rotational bands have been established to high spin in doubly odd I-118 using high-fold gamma-ray coincidence data collect ed with the Eurogam II spectrometer. Two of the bands are linked by di pole transitions at low spin and are believed to be signature partners built on the pi h(11/2) x nu h(11/2) structure. A low-spin signature inversion is observed and taken as evidence for a triaxial shape with gamma > 0 degrees, which is supported by TRS cranking calculations. Th e third band, seen at higher spin/frequency, is tentatively associated with a deformed five-particle-two-hole configuration, whereby two g(9 /2) proton holes result from two-particle-two-hole excitations across the Z = 50 shell gap.