Search

High-spin states in 84Rb have been studied by using the 70Zn (18O, p3n) 84Rb reaction at a beam energy of 75 MeV. The γ - γ coincidence, excitation function and ratios for directional correlation of oriented states were performed. A new level scheme was established in which the positive and negative parity bands have been extended up to 17+ and 17- with excitation energy about 7 MeV. The signature splitting and signature inversion of the positive parity yrast bands were observed and are discussed.

Mean lifetimes of the h11/2 quasineutron band in 129Ce were measured by using the Doppler shift attenuation method in connection with the reaction 116Sn (16O, 3n)129Ce at a bombarding energy of 73 MeV. The data indicate that transition quadrupole moment of 129Ce is smaller than that of 128Ce. This reduction in collectivity caused by the addition of an h11/2 neutron can be interpreted as due to triaxiality induced by γ driving effect.

Lifetimes of the high spin states in the negative parity band of 126Ba were measured by using the Doppler shift attenuation method in conjunction with the reaction 116Sn(16O, 2p4n)126Ba at a beam energy of 73 MeV. This band shows a typically collective behavior and possesses a near-axial prolate shape with a deformation parameter β2 = 0.27 ± 0.01 and triaxiality γ ~ -5°.