Influence of pairing correlations on E1 transition probabilities in odd-mass deformed, rare-earth nuclei

Abstract

Theoretical calculations of E1 and E3 transition rates for deformed rare-earth nuclei are made, taking into account the retarding effect of pairing correlations. It is found that pairing correlation correction factors R improve the general agreement with experiment for one class of transition, viz. E1 with ΔK = ± 1. However, the factors R generally cause poorer agreement for E1 with ΔK = 0 and for E3 than results from simple use of Nilsson single-particle wave functions with no pairing corrections. The importance of taking into account wave function components admixed by the Coriolis coupling is illustrated by a calculation fitting the many E1 transition rates between two bands in Hf 177. It is further suggested that effects due to three- quasi-particle components (or, in other language, octopole phonon or “effective charge” effects) are probably of great importance and deserve further study.