Nuclear matter density distributions of the neutron-rich He-6,He-8 isotopes from a sum-of-Gaussian analysis of elastic proton scattering data at intermediate energies

Differential cross sections for elastic p-He-6 and p-He-8 scattering, measured in inverse kinematics at high momentum transfer up to the first diffraction minimum and at projectile energies around 700 MeV/u at GSI Darmstadt, are analyzed applying the sum-of-Gaussians (SOG) method based on the Glauber multiple-scattering theory. The rms point matter radii of He-6 and He-8 are deduced to be 2.29(6) fm and 2.53(7) fm, respectively, in close agreement with those from former analyses using phenomenological parametrizations for describing the matter distributions. With the aid of the measurement at high momentum transfer, the overall radial density distributions of He-6 and He-8 are precisely deduced using the SOG method, in particular at small radii. A pronounced core rearrangement by adding the valence neutrons to an a-like core to form He-6 and He-8 is elucidated, and briefly discussed.

Automated summary

The differential cross sections for elastic p-He-6 and p-He-8 scattering, measured at high momentum transfer up to the first diffraction minimum and around 700 MeV/u at GSI Darmstadt, were analyzed using the sum-of-Gaussians (SOG) method based on Glauber multiple-scattering theory. The rms point matter radii of He-6 and He-8 were deduced to be 2.29(6) fm and 2.53(7) fm, respectively, in close agreement with former analyses. The overall radial density distributions of He-6 and He-8 were precisely deduced, particularly at small radii, revealing a pronounced core rearrangement when adding valence neutrons to form He-6 and He-8.