Nuclear alternating parity bands and transition rates in a model of coherent quadrupole-octupole motion in neutron-rich barium isotopes

Deformed even-even nuclei Barium isotopes with quadrupole-octupole deformations are investigated on the basis of a collective model. The model describes energy levels of the yrast band with alternating parity in the neutron-rich ^{140,142,144,146,148}Ba. The structure of the alternating parity bands is examined by odd-even (ΔI = 1) staggering diagrams. An analytical method of the collective model is proposed for the calculation of E2 transition probabilities in alternating spectra of the nuclei ^{140,142,144,146}Ba. (authors)