O16+Ca48reaction at 56 MeV. I. Transitions to resolved levels

All direct reaction channels of significant strength ($\sigma \ge 50$ μb) in the ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$ + ${}_{}{}^{48}{}_{}{}^{}\mathrm{Ca}$ reaction at $E_{\mathrm{lab}}\left({}_{}{}^{16}{}_{}{}^{}\mathrm{O}\right)=56\mathrm{}$ MeV were measured using a $\Delta E-E$ time-of-flight telescope system. Excitation spectra with energy resolutions $\approx 200$ keV full width at half maximum were obtained for outgoing ions ${}_{}{}^{11,12,13}{}_{}{}^{}\mathrm{B}$, ${}_{}{}^{12,13,14,15}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{14,15,16,17}{}_{}{}^{}\mathrm{N}$, and ${}_{}{}^{16,17,18,19}{}_{}{}^{}\mathrm{O}$. Angular distributions were obtained for the strongest transitions observed in inelastic scattering, the single-nucleon transfer reactions (${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{15}{}_{}{}^{}\mathrm{N}$) and (${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{17}{}_{}{}^{}\mathrm{O}$), the two-nucleon transfer reactions (${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$), (${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{14}{}_{}{}^{}\mathrm{N}$), and (${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{18}{}_{}{}^{}\mathrm{O}$), the three-nucleon transfer reactions (${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$), and the "exotic" transfers (${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{16}{}_{}{}^{}\mathrm{N}$) and (${}_{}{}^{16}{}_{}{}^{}\mathrm{O}$, ${}_{}{}^{15}{}_{}{}^{}\mathrm{C}$). Comparison of distorted-wave Born-approximation calculations for inelastic scattering, and for one- and two-nucleon transfer reactions to experiment suggest that reaction processes more complex than the one-step process are quite important in a majority of the transitions studied.