Systematics in back-angle alpha-particle scattering: Sc, Ti, V, and Cr isotopes

Elastic $\alpha$-scattering cross sections from ${}_{}{}^{45}{}_{}{}^{}\mathrm{Sc}$, ${}_{}{}^{49,50}{}_{}{}^{}\mathrm{Ti}$, ${}_{}{}^{50,52,53}{}_{}{}^{}\mathrm{Cr}$, and ${}_{}{}^{50,51}{}_{}{}^{}\mathrm{V}$ have been measured between 140° and 180° at a bombarding energy of $E_{\alpha } \left(\mathrm{lab}\right)=25\mathrm{}$ MeV. All angular distributions are similar and show no evidence of an anomalous backward enhancement. No evidence for a spin dependence of the cross section, within experimental uncertainties, is found for these nuclei, where the spins range from $I=0\mathrm{} ({}_{}{}^{50}{}_{}{}^{}\mathrm{Ti},{}_{}{}^{50}{}_{}{}^{}\mathrm{Cr}) \mathrm{to} I=6\mathrm{} \left({}_{}{}^{50}{}_{}{}^{}\mathrm{V}\right)$. Back-angle integrated cross sections (140°-180°) are compared with neighboring target nuclei between $A\approx 40$ and $A\approx 60$.