Elastic and inelastic scattering of [alpha] particles and protons from ¹⁴⁴SM and ¹³⁸BA

Abstract

Differential cross sections for the elastic scattering and inelastic scattering to the low-lying states in ¹⁴⁴Sm and ¹³⁸Ba have been measured using 50 MeV α particles and 30 MeV protons on ¹⁴⁴Sm and 50 MeV α particles on ¹³⁸Ba. The angular distributions are analyzed in the distorted wave Born approximation, employing collective model form factors. Spin and parity assignments of 2⁺, 3⁻, and 4⁺ are verified for states at 2.45 MeV. In ¹³⁸Ba spin and parity assignments of 2⁺, 4⁺, and 3⁻ are verified for states at 1.436, 1.898 and 2.880 MeV. Assignments of 2⁺ and 4⁺ are made for states at 2.19 and 2.27 MeV. Tentative assignment of 2⁺ and 4⁺ are made for members of unresolved doublets at 3.34 and 3.50 MeV, respectively. β[subscript cursive lowercase L]R values are given for all observed states. Reasonable agreement is obtained between these results and previous experimental data and recent theoretical calculations.