Low-energy transfer cross section for Borromean halo nuclei

We describe a schematic coupled-channels transfer calculation for the reaction {sup 6}He+{sup 238}U at near-barrier energies. We also present a simple semiclassical DWBA calculation of the two-neutron transfer. Both calculations are meant to supply the conditions under which the transfer cross section becomes much larger than the complete fusion one at subbarrier energies. It seems that a feasible mechanism is the incoherent contributions of two or more processes with quite different Q values.