Few-body calculations of proton-6,8Hescattering

We present a theoretical analysis of recently published experimental data for the elastic scattering of protons from the helium isotopesHe andHe at energies near 700 MeV per nucleon. The analysis treats the few-body degrees of freedom of these light neutron-rich nuclei explicitly and is developed in terms of threeand five-body wave functions forHe andHe, respectively. Comparisons of calculations with the data show that the sizes of the He nuclei consistent with such an analysis are larger by about 0.2 fm than those deduced from a more approximate procedure in which the structure of the weakly bound nuclei enters only through an assumed nuclear matter density. @S0556-2813 ~98!06504-2#