Shape Coexistence And Electric Monopole Transitions In Pt-184

Levels in 184Pt were studied from the decay of mass-separated 184Au by gamma-ray and conversion-electron spectroscopy and by gamma-ray angular distributions from low-temperature nuclear orientation. In addition to coexisting K(pi)=0+ bands, coexisting K(pi)=2+ bands are observed at low energy. Strong interband electric monopole transitions are observed between states of the two K(pi)=0+ bands and also between states of the two K(pi)=2+ bands. The coexistence of K(pi)=2+ bands at low energy represents a new type of collective structure.