Nature of the lowest excited Kπ=0+ states of even-even deformed nuclei

A recent paper by Casten and von Brentano [Phys. Rev. C 50, R2180 (1994)] has proposed on the basis of interacting-boson approximation calculations that the lowest excited Kπ=0+ states of deformed nuclei should be given a new interpretation as phonon excitations based on the gamma vibrations. The main argument for this reinterpretation is the observation of large E2 strengths coupling the Kπ=0+ and gamma bands in many nuclei. However, these strengths could arise from rather minor double-γ-phonon admixtures in the Kπ=0+ bands, and the dominant components of these complex states could have a quite different character.