The distorted-wave Born approximation (DWBA) cross section is discussed for a reaction of the form $A(d,pn)A$ in which $n$ is not observed. We evaluate the slowly convergent oscillating radial integrals by contour integration in the complex radius plane. This avoids the computation of wave functions out to the large distances that the Huby-Mines technique requires. The present technique is also useful for stripping to very weakly bound states. We find that the DWBA angular distribution for stripping to a resonant $n$ state is closely reproduced by using a form factor for the resonant energy of $n$. The width of the resonance, rather than the spectroscopic factor, is found to be measured by the absolute magnitude of the cross section. The results of calculations with the present method are compared with the results of the Huby-Mines method for the ${}_{}{}^{16}{}_{}{}^{}\mathrm{O}\mathrm{}(d,p)\mathrm{}{}_{}{}^{17}{}_{}{}^{}\mathrm{O}$ reaction leading to the resonant 5.08-MeV state of ${}_{}{}^{17}{}_{}{}^{}\mathrm{O}$.

• Received 8 May 1970

DOI:https://doi.org/10.1103/PhysRevC.2.782