Possible hexadecapole vibrations in 190, 192Os

The low-lying level structures of 190Os and 192Os have been investigated by the (t, α) proton pick-up reaction with 15 MeV tritons. In both nuclides this reaction strongly excites the I,Kπ = 4,4+ levels which were previously interpreted as two-phonon γ-vibrational states. The large two-quasiproton amplitude which seens to be implied by these results is inconsistent with the two-phonon description. However, the cross sections for these states are correctly predicted when the levels are assumed to be hexadecapole vibrations.