Vibrational excitations and tilted rotation in163Lu

Using a microscopic self-consistent model, we analyse the excitation built upon the rotational band in 163 Lu, which has been identified as a wobbling excitation on top of the rotation of a triaxial, strongly deformed shape. We find that the presence of pairing correlations substantially affects the energy of the excitation. Our calculations predict the onset of tilted rotation at a critical rotational frequency where the energy of the excitation approaches zero.