Inelastic Proton Scattering from Nuclei with 28 Neutrons

Abstract

The inelastic scattering of 17.45-MeV protons from ${\mathrm{Ti}}^{50}$, ${\mathrm{Cr}}^{52}$, ${\mathrm{Fe}}^{54}$, and ${\mathrm{V}}^{51}$ has been measured. Levels up to 5-MeV excitation were studied and the 30°-90° differential cross sections were measured for most of the levels. Spins and parities were assigned on the basis of the angular distributions and agree well with other experiments. The strength of the various inelastic cross sections were studied using a direct reaction theory with distorted waves. Both the collective model and the shell model of nuclear structure were used to describe the nuclear states. In describing the excitation of the strongly excited levels of the even-$A$ nuclei, the collective model picture yielded a strength parameter, ${\beta }_l$, which agreed within experimental error with the ${\beta }_l$ value extracted from Coulomb excitation experiments. The shell-model formulation described this data as well using a two-body Gaussian potential of finite range and depth of 45 MeV. The analysis of ${\mathrm{V}}^{51}$, however, was better explained using a shell-model analysis.