MEASUREMENTS OF DIFFERENTIAL CROSS-SECTION RATIOS FOR SINGLE-NUCLEON TRANSFER-REACTION PAIRS NEAR A = 25

Differential cross sections for the (d, p), (He-3, d), (alpha, t), and (alpha, He-3) reactions involving seventy-one residual states in Na-23, Mg-25, Al-25, and Al-27 have been measured at a forward angle with incident energies of 17.5, 20.2, 34.8, and 34.8 MeV, respectively. The ratio of cross-section pairs involving formation of the same residual state is determined for forty-five cases where both the angular momentum transfer and single-particle spectroscopic strength have been previously established. These are compared to values calculated with conventional distorted-wave Born approximation analyses, and the utility of this technique for identifying some levels which are possible s- or p-wave resonances is demonstrated and discussed for states in the vicinity of proton thresholds. An application is made involving proton threshold states in Al-27.