Electric quadrupole and hexadecapole moments in the transitional nuclei 150Nd, 152Sm, 154Sm, 154Gd and 156Gd

Abstract

Electric quadrupole and hexadecapole transition matrix elements were measured for 150Nd, 154Gd and 156Gd in Coulomb excitation experiments with 4He projectiles. The measured excitation probabilities are analyzed in the framework of the rotation-vibration coupling model. The following reduced E2 and E4 transition matrix elements are obtained for 150Nd, 154Gd and 156Gd, respectively: 〈2 +∥ M(E2)∥0 +〉 = 1.650 ± 0.012 e · b, 1.958 ± 0.011 e · b, 2.142 ± 0.020 e · b; and 〈4 +∥ M(E4)∥0 +〉 = 0.30 −0.07 +0.06 e · b 2, 0.64 −0.07 +0.06 e · b 2, 0.41 −0.18 +0.12 e · b 2. Previous Coulomb excitation experiments performed in this laboratory are also analyzed using this model and yield the following results for 152Sm and 154Sm, respectively: 〈2 +∥ M( E2)∥0 +〉 = 1.864 ± 0.017 e · b, 2.072 ± 0.010 e · b; and 〈4 +∥ M(E4)∥0 +〉 = 0.46 ± 0.08 e · b 2, 0.57 ± 0.09 e · b 2. Charge deformation parameters, β 2 and β 4, are deduced from the measured transition moments.