Nuclear induced breakup of halo nuclei

We investigate the validity of approximations that are sometimes made in calculating the nuclear induced breakup of halo nuclei. We find that a truncated coupled-channels calculations, in which the nuclear couplings between continuum states are ignored, gives almost the same result as a first-order calculation. However, the couplings are much too strong to justify these approximations. This is demonstrated in the frozen limit of a semiclassical description, where one can compare to exact results. We find in this limit that the one-neutron removal cross section of ¹¹Be obtained in the approximate treatment is much larger than the exact result. This trend is also indicated at low energy by comparing a perturbative calculation of the breakup of ⁸B to the result of a more realistic treatment, which evolves the wave function of the valence proton essentially to all orders in the target fields.