Second and fourth moments of the charge density and neutron-skin thickness of atomic nuclei

Abstract

A method to extract the neutron-skin thickness of atomic nuclei from the second and fourth moments of the charge density distribution is discussed. To reduce the error in the estimation of the neutron root-mean-square radius due to small effects like the magnetic form factors of nucleons, two neighbouring even-even isotopes are used. It is found that uncertainty of the neutron radius strongly depends on the accuracy of estimation of the fourth moment of the proton density distribution. Consequently, extracting the neutron-skin thickness from the charge second and fourth moments is hardly feasible.