Rotational bands and signature inversion phenomena in πh9/2⊗νi13/2 and πi13/2⊗νi13/2 structures in odd-odd 176Ir
Abstract:High-spin states in 176Ir have been investigated via the 149Sm(31P,4nγ) 176Ir reaction through excitation functions, X-γ and γ-γ coincidence measurements. Four rotational bands have been identified for the first time and their configurations are suggested on the basis of the existing knowledge of band structures in odd-odd nuclei as well as the measured in-band B(M1)/B(E2) ratios. Among the four bands observed, the πh9/2⊗νi13/2 and πi13/2⊗νi13/2 bands exhibit an anomalous signature splitting. The signature inversion point is observed in the former at Ic = 18? which is consistent with expectations; this signature inversion spin in the πi13/2⊗νi13/2 band may be larger than 25?. The combined effects of Coriolis and p-n residual interactions involved in such an inversion phenomenon have been discussed qualitatively.