Parity doublet bands with K=$0^{\pm }$ implying reflection asymmetry (with an average spacing between the levels of the same spin and opposite parity of 12.6 keV) are observed in ${}_{}{}^{224}{}_{}{}^{}\mathrm{Ac}$. In the strong coupling limit all K=$0^{\pm }$ parity doublet bands are shown to be constrained to Newby splittings with the same absolute magnitude, but with opposite sign. Experimentally, the Newby splittings in ${}_{}{}^{224}{}_{}{}^{}\mathrm{Ac}$ approach this theoretical expectation.

• Received 7 May 1991

DOI:https://doi.org/10.1103/PhysRevC.44.R1732