Equation of state and radii of finite nuclei in the presence of a diffuse surface layer

2017 American Physical Society. The definitions of nuclear surface and nuclear radii are considered within the Gibbs-Tolman-Rowlinson-Widom (GTW) approach. We demonstrate the nonmonotonic behavior of the nuclear equimolar radii, which is due to the shell effects in the chemical potential of finite nuclei. The direct variational method within the extended Thomas-Fermi approximation is used to establish the equation of state for finite nuclei. We have studied the influence of the polarization effect caused by the neutron excess on the particle density and the nuclear radii. This effect increases with the asymmetry parameter X and can be responsible for the appearance of large neutron halos in nuclei well away from the stability line. We have performed new calculations of the A dependence of the radii R(A) of nucleon distribution, which are based on the use of the experimental data for the nuclear binding energy. We demonstrate the presence of the quantum shell effects in R(A). We have analyzed the value of the neutron-skin thickness rnp in the isotopes of the Na, Sn, and Pb nuclei within the GTW approach and show the appearance of nonmonotonic behavior of rnp as a function of the neutron excess. We discuss the relative contributions to the neutron-skin thickness rnp from the skin and the halo effects.

Equation of state and radii of finite nuclei in the presence of a diffuse surface layer Academic Article