Sizes and interactions of halo nuclei

Abstract Theories of reactions of composite nuclei simplify considerably at energies of several 100 MeV/nucleon. Here Glauber methods provide a quantitative microscopic framework with a clear delineation of nucleon-nucleon scattering and nuclear structure inputs. However further approximations, tested for stable nuclei, are inappropriate for few-body halo nuclei with implications for analyses of both total reaction and elastic scattering cross sections. At lower projectile energies, of order tens of MeV/nucleon, reactions are more usefully formulated in terms of the optical interactions of the projectile constituents and the target, however corrections to Glauber theory are now large. A framework for improving such calculations at lower energies is also presented.