(C12,Be8) reaction on even calcium isotopes

The (${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$,${}_{}{}^8{}_{}{}^{}\mathrm{Be}$) reaction on even calcium isotopes results in selectively populated energy spectra similar to those for the (${}_{}{}^6{}_{}{}^{}\mathrm{Li},d$) and (${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$,${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$) reactions on the same target nuclei. The (${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$,${}_{}{}^8{}_{}{}^{}\mathrm{Be}$) cross sections are larger than those for (${}_{}{}^6{}_{}{}^{}\mathrm{Li},d$) and comparable to those for (${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$,${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$), and the cross sections decrease in magnitude for the heavier residual isotopes. Both effects are due largely to differences in the matching of $Q$ value and angular momentum. The (${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$,${}_{}{}^8{}_{}{}^{}\mathrm{Be}$) angular distributions have characteristics typical of direct reactions and the distributions are well reproduced by finite range distorted-wave Born-approximation calculations assuming direct transfer of an $\alpha$ particle.