COLLECTIVE STATES OF EVEN-EVEN AND ODD NUCLEI WITH BETA(2), BETA(3),..., BETA(N) DEFORMATIONS

Simple analytic expressions are derived for the energies of vibrationa l-rotational bands both of positive and negative parity in soft nuclei with nonvanishing equilibrium deformations beta(2)(0), beta(3)(0), .. ., beta(N)(0). 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 Ba-144,Ba-146, Ce-146, (146, 148,150) Nd, Pm-151, Sm-150, Rn-220,Rn-222, Fr-217,Fr-219,Fr-221 ,Ra-2 22,Ra-223,Ra-224,Ra-225,Ra-226,Ra-227,Ra-228, Ac-219,Ac-223,Ac-225,Ac- 227 and 1,Th-222,Th-223,Th-224,Th-225,Th-226,Th-228,Th-229 isotopes. T he correlation between experimental and theoretical values of the bran ching ratio B(E1,I --> I - 1)/B(E2,I --> I - 2) for some isotopes is s atisfactory. The calculated values of the ratios B(E1,I --> I - 1)/B(E 1,1 --> 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 availab le for Ra-226.