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

A method is presented to extract the neutron-skin thickness of atomic nuclei from the second and fourth moments of the electric charge distribution. We show that the value of the proton fourth moment must be independently known in order to estimate the neutron-skin thickness experimentally. To overc...

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Bibliographic Details
Authors: Naito, Tomoya, Colò, Gianluca, Liang, Haozhao, Roca Maza, Xavier
Format: article
Status:Published version
Publication Date:2021
Country:España
Institution:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repository:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2445/215906
Online Access:https://hdl.handle.net/2445/215906
Access Level:Open access
Keyword:Física nuclear
Estructura nuclear
Teoria del funcional de densitat
Nuclear physics
Nuclear structure
Density functionals
Description
Summary:A method is presented to extract the neutron-skin thickness of atomic nuclei from the second and fourth moments of the electric charge distribution. We show that the value of the proton fourth moment must be independently known in order to estimate the neutron-skin thickness experimentally. To overcome this problem, we propose the use of a strong linear correlation among the second and fourth moments of the proton distribution as calculated with several energy density functionals of common use. We take special care in estimating the errors associated with the different contributions to the neutron radius and show, for the first time, the analytic expressions for the spin-orbit contribution to the charge fourth moments of neutrons and protons. To reduce the uncertainty on the extraction of the neutron radius, two neighboring even-even isotopes are used. Nevertheless, the error on the fourth moment of the proton distribution, even if determined or assumed with large accuracy, dominates and prevents the present method from being applied for a sound determination of the neutron-skin thickness.