Matter radii of light halo nuclei

We reexamine the matter radii of diffuse halo nuclei, as deduced from reaction cross section measurements at high energy. Careful consideration is given to the intrinsic few-body structure of these projectiles and the adiabatic nature of the projectile-target interaction. Using {sup 11}Li, {sup 11}Be, and {sup 8}B as examples we show that data require significantly larger matter radii than previously reported. The revised value for {sup 11}Li of 3.55fm is consistent with three-body models with significant 1{ital s}-intruder state components, which reproduce experimental {sup 9}Li momentum distributions following {sup 11}Li breakup, but were hitherto thought to be at variance with cross section data. {copyright} {ital 1996 The American Physical Society.}