Octupole Deformation Bands of πh _ll/2 in Neutron-Rich ^145,147La Nuclei

Octupole deformation bands built on πh _ll/2 orbital in neutron-rich odd-Z ^145,147La nuclei have been investigated by measuring the prompt γ-rays emitted from the ²⁵²Cf source. The alternating parity band structures and strong E1 transitions observed between negative- and positive-parity bands in both nuclei indicate the octupole deformation enhanced by the h _ll/2 single proton coupling. According to observed energy displacements the octupole deformation becomes stable at the intermediate spin states.