On the enhanced E1 transitions in the K = 3/2 parity doublet band in 223Ra

Abstract

We have applied the fast timing βγγ(t) technique to remeasure lifetimes of selected states in 223Ra populated in the β- decay of 223Fr. T1/2 = 587(12) ps and 210(13)ps have been obtained for the 3/2- and 5/2- states at 50.1 and 79.7 keV, that are more accurate than the previous values of 630(70)ps and 166(55)ps, respectively. Our |D0| value of 0.155(10) e·fm obtained for the K=3/2 configuration together with the available values of |D0| for the K=1/2 and K=5/2 parity doublet bands establish the configuration dependence of |D0| at low spins in this nucleus. Results of theoretical calculations performed for 223Ra, using the quasiparticle-phonon model (QPM) with inclusion of the Coriolis coupling, reasonably well reproduce octupole correlations in this nucleus.