Nuclear breakup of Borromean nuclei

We study the eikonal model for the nuclear-induced breakup of Borromean nuclei, using {sup 11}Li and {sup 6}He as examples. The full eikonal model is difficult to realize because of six-dimensional integrals, but a number of simplifying approximations are found to be accurate. The integrated diffractive and one-nucleon stripping cross sections are rather insensitive to the neutron-neutron correlation, but the two-nucleon stripping does show some dependence on the correlation. The distribution of excitation energy in the neutron-core final state in one-neutron stripping reactions is quite sensitive to the shell structure of the halo wave function. Experimental data favor models with comparable amounts of s and p waves in the {sup 11}Li halo. {copyright} {ital 1998} {ital The American Physical Society}