Analysis of Li-8(alpha, n)B-11 below the Coulomb barrier in the potential model

The reaction Li-8(alpha, n)B-11 is of interest in inhomogeneous big bang nucleosynthesis. A distorted wave Born approximation calculation employing folding potentials is presented for energies below the Coulomb barrier. The recently observed resonance at about 540 keV center-of-mass energy can be reproduced. The astrophysical S factor is calculated for the ground-state transition as well as for the transitions to the first four excited states of B-11. The reaction rate is derived and compared to literature data. The inclusion of the excited states increases the rate by a factor of 1.5 compared to the ground-state transition.