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arXiv · 2106.10378

Charge Radius of Neutron-deficient $^{54}$Ni and Symmetry Energy Constraints Using the Difference in Mirror Pair Charge Radii

Skyy V. Pineda·Kristian König·Dominic M. Rossi·B. Alex Brown·Anthony Incorvati·Jeremy Lantis·Kei Minamisono·Wilfried Nörtershäuser·Jorge Piekarewicz·Robert Powel·Felix Sommer
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Abstract

The nuclear root-mean-square charge radius of $^{54}$Ni was determined with collinear laser spectroscopy to be $R(^{54}$Ni) = 3.737\,(3)~fm. In conjunction with the known radius of the mirror nucleus $^{54}$Fe, the difference of the charge radii was extracted as $ΔR_{\rm ch}$ = 0.049\,(4)~fm. Based on the correlation between $ΔR_{\rm ch}$ and the slope of the symmetry energy at nuclear saturation density ($L$), we deduced $20 \le L \le 70$\,MeV. The present result is consistent with the $L$ from the binary neutron star merger GW170817, favoring a soft neutron matter EOS, and barely consistent with the PREX-2 result within 1$σ$ error bands. Our result indicates the neutron-skin thickness of $^{48}$Ca as 0.15\,-\,0.19\,fm.

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Skyy V. Pineda, Kristian König, Dominic M. Rossi, B. Alex Brown, Anthony Incorvati, Jeremy Lantis, Kei Minamisono, Wilfried Nörtershäuser, Jorge Piekarewicz, Robert Powel, Felix Sommer. 2021-06-18. Charge Radius of Neutron-deficient $^{54}$Ni and Symmetry Energy Constraints Using the Difference in Mirror Pair Charge Radii. https://doi.org/10.1103/physrevlett.127.182503

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