Collective states of even-even and odd nuclei with β2, β3, …, βN deformations

Abstract

Simple analytic expressions are derived for the energies of vibrational-rotational bands both of positive and negative parity in soft nuclei with nonvanishing equilibrium deformations β20, β30, …, βN0. Expressions for the reduced probabilities of E1, E2 and E3 transitions are derived. The calculated values of energies are in good agreement with experimental data for 144,146Ba, 146Ce, 146,148,150Nd, 151Pm, 150Sm, 220,222Rn, 217,219,221Fr, 218,219,220,221,222,223,224,225,226,227,228Ra, 219,223,225,227Ac and 220,221,222,223,224,225,226,228,229Th isotopes. The correlation between experimental and theoretical values of the branching ratio B(E1, I → I − 1)B(E2, I → I − 2) for some isotopes is satisfactory. The calculated values of the ratios B(E1, I → I − 1)B(E1, 1 → 0), B(E2, I → I − 2)B(E2, 2 → 0) and B(E3, I → I − 3)B(E3, 3 → 0) are in satisfactory agreement with experimental data available for 226Ra.