Analysis of theC12(p, α)B9Reaction at 44.5 MeV

A distorted-wave Born-approximation theory is described which uses a combination of square-well and harmonic-oscillator potentials in the local energy approximation to take account of the finite-range effects in ($p, \alpha$) direct pickup reactions. A fit was obtained to the forward part of the ${\mathrm{C}}^{12}(p, \alpha ){\mathrm{B}}^9$ angular distribution which gives agreement with the calculated spectroscopic factor. In contrast, no reasonable set of parameters was found which could fit the experimentally observed peak at backward angles, providing some supporting evidence that it is probably caused by an exchange process.