Breakup Coupling Effects on Near-Barrier

New data for near-barrier Li, Be and B + Ni elastic scattering enable a comparison of breakup coupling effects for these loosely-bound projectiles. Coupled Discretised Continuum Channels (CDCC) calculations suggest that the large total reaction cross sections for B + Ni are dominated by breakup at near-barrier energies, unlike Li and Be where breakup makes a small contribution. In spite of this, the CDCC calculations show a small coupling influence due to breakup for B, in contrast to the situation for Li and Be. An examination of the S matrices gives a clue to this counter-intuitive behaviour.