Alpha-particle spectroscopic strengths using the (p,pα) reaction at 101.5 MeV

Proton-alpha particle coincidence spectra from 101.5 MeV ($\mathrm{p},\mathrm{p}\alpha$) reactions on ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{20}{}_{}{}^{}\mathrm{Ne}$, ${}_{}{}^{24}{}_{}{}^{}\mathrm{Mg}$, ${}_{}{}^{28}{}_{}{}^{}\mathrm{Si}$, ${}_{}{}^{32}{}_{}{}^{}\mathrm{S}$, ${}_{}{}^{40}{}_{}{}^{}\mathrm{Ca}$, ${}_{}{}^{48}{}_{}{}^{}\mathrm{Ti}$, ${}_{}{}^{54}{}_{}{}^{}\mathrm{Fe}$, and ${}_{}{}^{66}{}_{}{}^{}\mathrm{Zn}$ have been obtained in a coplanar geometry at quasifree angle pairs for each target. A missing energy resolution of $\lesssim 450$ keV was sufficient to separate the lowlying states of the residual nuclides. Data for ground-state transitions, and for eight excited states were obtained and compared with distorted-wave impulse approximation calculations. The targetmass dependence of the resultant relative ground-state spectroscopic factors is reasonably consistent with that obtained from (${}_{}{}^6{}_{}{}^{}\mathrm{Li}$,d) reactions. The corresponding absolute spectroscopic factors are larger than shell-model predictions, but sensitive to the bound-state parametrization. However, the spectral shapes do constrain the range of possible bound-state rms radii. The fits to the excited states are less satisfactory.