Direct determination of the neutron skin thicknesses in $^{40,48}$Ca from proton elastic scattering at $E_p = 295$ MeV

J. Zenihiro; H. Sakaguchi; S. Terashima; T. Uesaka; G. Hagen; M. Itoh; T. Murakami; Y. Nakatsugawa; T. Ohnishi; H. Sagawa; H. Takeda; M. Uchida; H. P. Yoshida; S. Yoshida; M. Yosoi

arXiv · 1810.11796

Direct determination of the neutron skin thicknesses in $^{40,48}$Ca from proton elastic scattering at $E_p = 295$ MeV

J. Zenihiro·H. Sakaguchi·S. Terashima·T. Uesaka·G. Hagen·M. Itoh·T. Murakami·Y. Nakatsugawa·T. Ohnishi·H. Sagawa·H. Takeda·M. Uchida·H. P. Yoshida·S. Yoshida·M. Yosoi

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Abstract

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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J. Zenihiro, H. Sakaguchi, S. Terashima, T. Uesaka, G. Hagen, M. Itoh, T. Murakami, Y. Nakatsugawa, T. Ohnishi, H. Sagawa, H. Takeda, M. Uchida, H. P. Yoshida, S. Yoshida, M. Yosoi. 2018-10-28. Direct determination of the neutron skin thicknesses in $^{40,48}$Ca from proton elastic scattering at $E_p = 295$ MeV. https://arxiv.org/abs/1810.11796

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