Determination of matter radius and neutron-skin thickness of $^{60,62,64}$Ni from reaction cross section of proton scattering on $^{60,62,64}$Ni targets (published in Results in Physics)

TL;DR

This study determines matter radii and neutron-skin thicknesses of nickel isotopes using proton scattering data and a folding model, providing new insights into nuclear structure with quantified uncertainties.

Contribution

It introduces a method to extract matter radii and neutron-skin thicknesses of $^{60,62,64}$Ni from reaction cross sections using the Kyushu $g$-matrix folding model with scaled densities.

Findings

Matter radii for $^{60,62,64}$Ni determined with high precision.

Neutron-skin thicknesses for these isotopes estimated with uncertainties.

Results consistent with previous measurements and theoretical models.

Abstract

In our previous work, we determined matter radii $r_{\rm m}({\rm exp})$ and neutron-skin thickness $r_{\rm skin}({\rm exp})$ from reaction cross sections $\sigma_{\rm R}({\rm exp})$ of proton scattering on $^{208}$Pb, $^{58}$Ni, $^{40,48}$Ca, $^{12}$C targets, using the chiral (Kyushu) $g$-matrix folding model with the densities calculated with Gogny-D1S-HFB (D1S-GHFB) with angular momentum projection (AMP). The resultant $r_{\rm skin}({\rm exp})$ agree with the PREX2 and CREX values. As for $^{58}$Ni, our value is consistent with one determined from the differential cross section for $^{58}$Ni+$^{4}$He scattering. As for p+$^{60,62,64}$N scattering, $\sigma_{\rm R}({\rm exp})$ are available as a function of incident energies $E_{\rm in}$, where $E_{\rm in}=22.8 \sim 65.5$~MeV for $^{60}$Ni, $E_{\rm in}=40,60.8$~MeV for $^{62}$Ni, $E_{\rm in}=40, 60.8$~MeV for $^{64}$Ni. Our aim is to determine matter radii $r_{\rm m}({\rm exp})$ for $^{60,62,64}$Ni from the $\sigma_{\rm R}({\rm exp})$. Our method is the Kyushu $g$-matrix folding model with the densities scaled from D1S-GHFB+AMP densities, Our skin values are $r_{\rm skin}({\rm exp})=0.076 \pm 0.019,~0.106 \pm 0.192,~0.162 \pm 0.176$~fm, and $r_{\rm m}({\rm exp})=3.759 \pm 0.011,~3.811 \pm 0.107,~3.864 \pm 0.101$~fm for $^{60,62,64}$Ni, respectively.