Deformation effect on nuclear density profile and radius enhancement in light- and medium-mass neutron-rich nuclei

Abstract

The mass number dependence of nuclear radii is closely related to the properties of nuclear matter. It is known that most nuclei exhibit some deformation. We discuss how the nuclear density profile is modified by nuclear deformation to elucidate the enhancement mechanism of nuclear radii through a systematic investigation of neutron-rich Ne, Mg, Si, S, Ar, Ti, Cr, and Fe isotopes. Skyrme–Hartree–Fock calculations are performed in a 3D Cartesian grid to describe the nuclear deformation in a non-empirical way. The role of nuclear deformation in nuclear density profiles is explored in comparison to calculations with a spherical limit. We find correlations between nuclear deformation and the internal nuclear density. The evolution of nuclear radii appears to follow the core swelling mechanism recently proposed in spherical nuclei [W. Horiuchi and T. Inakura, Phys. Rev. C 101, 061301(R) (2020)], and the radius is further enhanced by nuclear deformation. This study demands further theoretical and experimental investigations for the internal density.