It is found that B(E1) values calculated by using a model in which one quasiparticle is coupled to a rotor are more than an order of magnitude too small compared with measured B(E1) values in low-energy transitions observed in the yrast spectroscopy of odd-A rare-earth nuclei. Thus, the measured B(E1) values are analyzed by introducing the parameters which effectively take into account the octupole softness. The parameters thus determined for two sets of bands in ${}_{}{}^{169}{}_{}{}^{}\mathrm{Lu}$ are considerably different. Interpreting the difference in terms of a difference in blocking of the particular orbitals in octupole vibration amplitudes, an estimate of the difference is made using a microscopic model. A full agreement between the estimated values and the values necessary for reproducing data is not obtained.

• Received 23 July 1992

DOI:https://doi.org/10.1103/PhysRevC.47.2008