Search for excited superdeformed bands in 151Dy

Following the first report of superdeformed (SD) bands with identical transition energies in the pairs (151Tb*,152Dy), (150Gd*, 151Tb) and (153Dy*, 152Dy) (where * denotes an excited SD band), it was proposed by Nazarewicz et al. that the observations could be understood in a strong-coupling approach if pseudo SU(3) symmetry were invoked. In this model there are three limiting values of the decoupling parameter; i.e. a = 0, ±1. In the first two cases mentioned above the pairs of bands have nearly identical transition energies and are interpreted as proton excitations involving the [200]1/2 pseudospin orbital coupled to the 152Dy core, for which the value of the decoupling parameter is calculated to be a =+1