High-Spin Level Systematics In Pt-186-194 And Rotation-Alignment Coupling

Systematic investigations of the shape-transitional nuclei $^{186}\mathrm{Pt}$ to $^{194}\mathrm{Pt}$ by ($\ensuremath{\alpha}, \mathrm{xn}\ensuremath{\gamma}$) reactions have revealed a rich variety of high-spin structural phenomena, which can be qualitatively understood in terms of rotation-alignment coupling and the interplay between collective and single-particle excitation modes. Acute backbending in the positive-parity yrast sequences of $^{188,190,192,194}\mathrm{Pt}$ is attributed to the intersection of rotation-aligned ($\ensuremath{\nu}{{i}_{\frac{13}{2}}}^{\ensuremath{-}2}$) and ($\ensuremath{\pi}{{h}_{\frac{11}{2}}}^{\ensuremath{-}2}$) bands with the ground bands.