Persisting domination of the octupole over the quadrupole degrees of freedom and the new type of transitional nuclei: High-spin behavior ofRa218

Abstract
High-spin states up to I=31 have been studied in the Ra218 nucleus and the staggering sequence of levels of positive and negative parity persists up to highest level. This observation supports the idea that in some nuclei the high-spin excitations may primarily be dominated by deformations which do not conserve the intrinsic parity (such as octupole, λ=3, and higher odd-λ multipolarities) rather than by the ‘‘usual’’ quadrupole (λ=2) and possibly higher even-λ multipolarities.