Nuclear matter distributions in the 6He and 8He nuclei from differential cross sections for small-angle proton elastic scattering at intermediate energy

A Glauber based analysis of the experimental cross sections for small-angle elastic p 6,8He scattering at 0.7 GeV has been performed. The radii and radial shape of the 6He and 8He nuclei have been determined using phenomenological nuclear density distributions with two free parameters. The deduced shapes of the 6He and 8He nuclear matter radial distributions conform with the concept that both nuclei consist of an α-particle core and a significant neutron halo. The accuracy of the theoretical analysis of the elastic-scattering cross-section data is discussed, and possible sources of systematic uncertainty related to some basic limitations in the applied method are outlined. The experimental p 6,8He elastic-scattering cross sections have also been utilized for probing the matter density distributions resulting from various nuclear microscopic models. Besides, the sensitivity of the total p 6,8He reaction cross sections to the size of the 6He and 8He nuclei has been considered