⁹Be(p→,d)⁸Be and ⁹Be(p→,α)⁶Li reactions at low energies

Angular distributions of cross section and vector analyzing power have been measured for the ⁹Be(p→,d)⁸Be and ⁹Be(p→,α)⁶Li reactions for 77<~E_p<~321 keV. Previous work has suggested that that the low-energy cross section is enhanced by the E_x=6.57 MeV subthreshold level in ¹⁰B. The analyzing power measurements are particularly sensitive to the presence of the subthreshold level, leading to a definitive test of the hypothesis. The data are analyzed in terms of R-matrix and direct reaction calculations. We find that the magnitude and angular distribution of the ⁹Be(p,d)⁸Be reaction at very low energies can be explained by the direct reaction mechanism without any contribution from the subthreshold resonance. The implications of these results for the stellar reaction rate of the ⁹Be(p,d)⁸Be and ⁹Be(p,α)⁶Li reactions are discussed.