High spin states in 172W, 174W and 176W studied by (16O,xn) reactions: decoupled quasiparticle bands and backbending

High spin states in 172W, 174W and 176W have been studied using γ-ray techniques following (16O,xn) reactions on enriched Dy targets. The ground state band has been shown to backbend in 174W and 176W, but not in 172W. Sidebands are populated in each nucleus, with preferential population of an odd-spin sequence in each case. The decay properties of these bands, which have negative parity, suggest that they are due to the partial decoupling of a pair of quasiparticles by the Coriolis force. The properties of the bands are used to estimate in an empirical way the properties of a rotation aligned (isub(13/2))2 neutron band in order to predict the systematics of backbending due to bandcrossing. (Author)