The nuclei ${}_{}{}^{138,140}{}_{}{}^{}\mathrm{Ce}$ have been studied by means of the ${}_{}{}^{140}{}_{}{}^{}\mathrm{Ce}(p, t)$, ${}_{}{}^{142}{}_{}{}^{}\mathrm{Ce}(p, t)$, and ${}_{}{}^{140}{}_{}{}^{}\mathrm{Ce}(p, p^{\prime })$ reactions at 30 MeV. Angular distributions have been measured from ${\theta }_{\mathrm{lab}}=16\mathrm{}° \mathrm{to} 64°$. The inelastic scattering data were analyzed with distorted-wave Born approximation to confirm multipolarities and extract deformation parameters for the strongly excited levels. The ($p, t$) data were also analyzed with distorted-wave Born approximation to obtain limits on the two-nucleon orbital angular momentum ($L$) transfer. This analysis, plus the empirical angular distribution shapes of levels with known $J^{\pi }$, permits us to suggest (or at least limit) $J^{\pi }$ values for many new levels. The ($p, t$) differential cross sections have been further analyzed in terms of simple two-neutron configurations through the enhancement factor concept. The two-neutron transfer results are discussed in terms of the pair vibration model.

NUCLEAR REACTIONS ${}_{}{}^{142,140}{}_{}{}^{}\mathrm{Ce}(p, t)$, ${}_{}{}^{140}{}_{}{}^{}\mathrm{Ce}(p, p^{\prime })$, $E_p=30\mathrm{}$ MeV; measured level energies and $\sigma \left(\theta \right)$; DWBA analysis, deformation parameters, enhancement factors.

• Received 1 November 1976

DOI:https://doi.org/10.1103/PhysRevC.15.903