2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/217073We re-examine 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 $^{11}$Li, $^{11}$Be and $^{8}$B as examples we show that data require significantly larger matter radii than previously reported. The revised value for $^{11}$Li of 3.55 fm is consistent with three-body models with significant $1s$-intruder state components, which reproduce experimental $^{9}$Li momentum distributions following $^{11}$Li breakup, but were hitherto thought to be at variance with cross section data.8 pages RevTeX plus 5 Postscript figures. Figures also available at http://www.ph.surrey.ac.uk/scnp/jakpub/figures.html Scheduled tentatively for 13May96 issue of Phys. Rev. LettNuclear Theorytext