New features of positive and negative parity rotational bands in 226Ra Original Research Article

Energies for three positive and three negative parity bands and E1 transition probabilities predicted by the extended coherent states model (ECSM) in 226Ra, are presented and new signatures for octupole deformation are pointed out. A new displacement energy function, more appropriate for a spectrum, exhibiting large deviations from a linear J(J+1) dependence, is used and a beat pattern is found. Two new alternative expressions for the E1 transition operator involving anharmonicities are introduced. Both of them are able to describe the gross behavior of the E1 matrix elements as function of the angular momentum. In particular the strong E1 transitions associated with the critical value of angular momentum where the octupole deformation is set on are fairly well obtained.