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 Li, Be, and B as examples we show that data require significantly larger matter radii than previously reported. The revised value for Li of 3.55 fm is consistent with three-body models with significant 1s-intruder state components, which reproduce experimental Li momentum distributions following Li breakup, but were hitherto thought to be at variance with cross section data. [S0031-9007(96)00289-X]