Complex band structure in neutron-deficient Hg-178

Using the GAMMASPHERE array in conjunction with the Fragment Mass Analyzer, the level structure of the near drip-line nucleus Hg-178 has been considerably expanded with the recoil-decay tagging technique. Of particular interest is a new rotational band which exhibits a complex decay towards the low spin states arising from both the prolate-deformed and the nearly spherical coexisting minima. It is proposed that this band is associated at low spin with an octupole vibration which is crossed at moderate frequency by a shape driving, two quasiproton excitation.