Experimental determination of the surface density for the ${}^6\mathrm{He}$ exotic nucleus

Angular distributions for the elastic scattering of ${}^{4,6}\mathrm{He}$ on ${}^{58}\mathrm{Ni}$ have been measured at near-barrier energies. The present data, combined with others for the ${}^4\mathrm{He}{+}^{58}\mathrm{Ni}$ system at intermediate energies, allowed the determination of the ${}^{4,6}\mathrm{He}$ ground-state nuclear densities through an unfolding method. The experimentally extracted nuclear densities are compared with the results of theoretical calculations.