\gamma-ray spectroscopy of 163Ta

M. Sandzelius et al.

Accepted Thursday Nov 05, 2009

Excited states in have been identified for the first time using the 106Cd(60Ni,3p) fusion evaporation reaction. Gamma rays were detected by the JUROGAM g-ray spectrometer and recoil discrimination was achieved by utilising the RITU gas-filled separator in conjunction with the GREAT spectrometer situated at the focal plane of RITU. The yrast states are assigned to a strongly-coupled rotational band based on a ph11/2 configuration. This structure exhibits a large signature splitting at low spins which disappears after the paired band crossing due to the alignment of a pair of i13/2 neutrons. This effect is ascribed to triaxial shape changes induced by the core polarizing properties of the deformation aligned h11/2 proton and the rotational aligned i13/2 neutrons. Two additional strongly coupled band structures have been established and are discussed in terms of octupole-vibrational and two-quasiparticle excitations built on the yrast structure. The experimental results are compared with predictions from cranked-shell model and total Routhian surface calculations.