Band structures in 116I Original Research Article

The band structures of the doubly-odd nucleus 116I have been studied by using in-beam γ-ray spectroscopy with the 103Rh(16O, 3n)116I reaction at an energy of Elab=80 MeV. The beam was provided by the 12UD tandem accelerator at the University of Tsukuba. Absolute excitation energies for the observed collective bands except for a band based on the π(h11/2)ν(g7/2) configuration have been definitely determined. The positive-parity rotational band based on the π(h11/2)ν(h11/2) configuration is built on the 8+ level at 874.3 keV and exhibits a spin inversion below I=14ℏ. A new vibration-like band built on the 8− level at 468.5 keV has been identified and can be interpreted as resulting from the π(g7/2)ν(h11/2) configuration coupled to the Te core vibration. A negative-parity band built on the 14− level at 2547.6 keV shows a vibration-like structure and terminates its collectivity at the 24− level at 6215.0 keV. The total Routhian surface calculations suggest a noncollective oblate state with β2=0.182 and γ=60° based on a fully aligned six-quasiparticle, π[h11/2(g7/2)2]ν[g7/2(h11/2)2], configuration for this 24− level. The excitation energy of the 7− isomer with T1/2=3.27 μs was found to be at 430.4 keV.