Four-body distorted wave theory for halo excitations

A microscopic approach to breakup reactions into the low-energy continuum of Borromean two-neutron halo nuclei is developed, taking quantum-mechanically into account both Coulomb and nuclear dissociation, simultaneously. The crucial role of both elastic and inelastic fragmentation is demonstrated for He-6 breakup on C and Pb targets at intermediate energies, for kinematically complete experiments. Recent GSI experimental data are for the first time analyzed quantitatively and reveal a rich and complex interplay of reaction mechanisms and low-lying halo excitations.