Beta-vibrations inO(6)-nuclei: A pair mode?

We investigate excitations of an intrinsic state allowing for quadrupole and pair deformations, in theSO (8)S, D-pair model, using the exact Schwinger boson realization and RPA. The 0⁺ head of the quasi-beta band in0 (6) nuclei which is generally interpreted as a shape vibration turns out to be a double pairing vibration. This has experimentally observable consequences for pair transfer strengths. It suggests also the interesting question whether pairing and beta vibrations are generally not independent, or would coexist in less schematic models. AnSU (8) boson model would allow for such more general situations which are briefly discussed.