Scaling and interference in the dissociation of halo nuclei

The dissociation of halo nuclei through their collision with light and heavy targets is considered within the continuum discretized coupled channels theory. We study the one-proton halo nucleus 8B and the one-neutron halo nucleus 11Be, as well as the more normal 7Be. The procedure previously employed to extract the Coulomb dissociation cross section by subtracting the nuclear one is critically assessed, and the scaling law usually assumed for the target mass dependence of the nuclear breakup cross section is also tested. It is found that the nuclear breakup cross section for halo nuclei scales with the mass of the target as AT1/3. However, it does not follow the same geometrical dependence found in non-halo nuclei such as 7Be. We find further that we cannot ignore Coulomb-nuclear interference effects, which may be constructive or destructive in nature, and so the errors in previously extracted B(E1) using the subtraction procedure are almost certainly underestimated.