Nuclear Size Comparison of Even Titanium Isotopes Using 140-MeV $\alpha$-Particle Scattering

Systematic variations in nuclear-matter distributions have been determined by analyzing the measured elastic scattering of 140-MeV alpha particles from ${}_{}{}^{46,48,50}{}_{}{}^{}\mathrm{Ti}$. The "unique" optical potentials obtained ($\frac{J_{\mathrm{R}}}{4A}\simeq 300$ MeV ${\mathrm{fm}}^3$, $\frac{J_{\mathrm{I}}}{4A}\simeq 100$ MeV ${\mathrm{fm}}^3$) indicate that isotopic differences occur primarily in the strength of the imaginary potential. The rms matter radii increase with $A$, in contrast to those of the charge distributions. The matter-radius results are in agreement with Hartree-Fock calculations.