Borroman Halo Nuclei: Continuum Structures and Reactions

Halo nuclei exhibit a new type of structure found in extremely neutron-rich light nuclei at the limits of nuclear existence. Of particular interest are Borromean nuclei, where none of the binary substructures can bind, demonstrating features of universality. Nuclear physics has in recent years taken further steps to explore the nature of the halo continuum, this being, in fact, the major part of the spectrum since halo nuclei support only one or a few bound states. Since 3 -> 3 scattering is prohibitively difficult to perform, the halo continuum has so far been excited in binary collisions, proceeding via the exotic ground state which to various degrees puts its imprint on the result. We discuss via examples how to disentangle continuum structures, comparing with recent correlation data, and the challenges of linking reaction theory and modern structure calculations.