SIZES AND INTERACTIONS OF HALO NUCLEI

Theories of reactions of composite nuclei simplify considerably at ene rgies of several 100 MeV/nucleon. Here Glauber methods provide a quant itative microscopic framework with a clear delineation of nucleon-nucl eon scattering and nuclear structure inputs. However, further approxim ations, tested for stable nuclei, are inappropriate for few-body halo nuclei with implications for analyses of both total reaction and elast ic scattering cross sections. At lower projectile energies, of order t ens of MeV/nucleon, reactions are more usefully formulated in terms of the optical interactions of the projectile constituents and the targe t, however, corrections to Glauber theory are now large. A framework f or improving such calculations at lower energies is also presented.