Deformed states of neutron-deficient cerium and neodymium nuclei

High-spin levels in Ce and Nd isotopes excited by the reactions ^120,122Sn(¹⁶O, 3n) ^{133, 135}Ce and ^{122, 124}Te(¹⁶O, 3n)^{135, 137}Nd have been studied by in-beam γ-ray spectroscopic methods (prompt and delayed spectra, excitation functions, angular distributions and γ-γ coincidences). Bands built on the $\text{11}\text{2}{}^{\mathrm{?}}$ isomeric levels in ¹³⁵Ce and ¹³⁷Nd and on the $\text{9}\text{2}{}^{\mathrm{?}}$ground states in ¹³³Ce and ¹³⁵Nd have been found. A prolate deformation is required for these nuclei in order to explain the E2/M1 mixing ratios and the level ordering of these bands.