Broad states beyond the neutron drip line -: Examples of 5H and 4n

Theoretical studies of broad states in the few-body systems beyond the neutron drip line have been performed. We introduce a theoretical model which allows to incorporate the initial structure of colliding nuclei, reaction mechanism, few-body effects and final-state interactions in studies of broad unbound states. The model is directly related to the sudden-removal approximation for high-energy knock-out or break-up reactions. We apply this model to qualitative studies of some general properties of broad few-body states including correlations for emitted fragments. The theoretical ideas are illustrated mainly using the example of H-5. The prospect for observation of broad continuum structures corresponding to the tetraneutron (4)n is also discussed.