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تسجيل مستخدم جديدDirect determination of the neutron skin thicknesses in $^{40,48}$Ca from proton elastic scattering at $E_p = 295$ MeV
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The neutron density distributions and neutron skin thicknesses in $^{40,48}$Ca are determined from the angular distributions of the cross sections and analyzing powers of polarized proton elastic scattering at $E_p = 295$ MeV. Based on the framework of the relativistic impulse approximation with the density-dependent effective $NN$ interaction, the experimental data is successfully analyzed, providing precise information of neutron and proton density profiles of $^{40,48}$Ca with small uncertainties. The extracted neutron and proton density distributions give neutron skin thicknesses in $^{40,48}$Ca for $-0.010^{+0.022}_{-0.024}$ fm and $0.168^{+0.025}_{-0.028}$ fm, respectively. The results of the density profiles and the neutron skin thickness in $^{48}$Ca are directly compared with the {it ab initio} coupled-cluster calculations with interactions derived from chiral effective field theory, as well as relativistic and non-relativistic energy density functional theories.
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{bf Background:} Using the chiral (Kyushu) $g$-matrix folding model with the densities calculated with GHFB+AMP, we determined $r_{rm skin}^{208}=0.25$fm from the central values of $sigma_{rm R}$ of p+$^{208}$Pb scattering in $E_{rm in}=40-81$MeV. Th
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