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 considerat ion is given to the intrinsic few-body structure of these projectiles and the adiabatic nature of the projectile-target interaction. Using L i-11, Be-11, and B-8 as examples we show that data require significant ly larger matter radii than previously reported. The revised value for Li-11 of 3.55 fm is consistent with three-body models with significan t 1s-intruder state components, which reproduce experimental Li-9 mome ntum distributions following Li-11 breakup, but were hitherto thought to be at variance with cross section data.