학술논문
Charge radii of $^{55,56}$Ni reveal a surprisingly similar behavior at $N=28$ in Ca and Ni isotopes
Document Type
Working Paper
Author
Sommer, F.; König, K.; Rossi, D. M.; Everett, N.; Garand, D.; de Groote, R. P.; Holt, J. D.; Imgram, P.; Incorvati, A.; Kalman, C.; Klose, A.; Lantis, J.; Liu, Y.; Miller, A. J.; Minamisono, K.; Miyagi, T.; Nazarewicz, W.; Nörtershäuser, W.; Pineda, S. V.; Powel, R.; Reinhard, P. -G.; Renth, L.; Romero-Romero, E.; Roth, R.; Schwenk, A.; Sumithrarachchi, C.; Teigelhöfer, A.
Source
Phys. Rev. Lett. 129, 132501 (2022)
Subject
Language
Abstract
Nuclear charge radii of $^{55,56}$Ni were measured by collinear laser spectroscopy. The obtained information completes the behavior of the charge radii at the shell closure of the doubly magic nucleus $^{56}$Ni. The trend of charge radii across the shell closures in calcium and nickel is surprisingly similar despite the fact that the $^{56}$Ni core is supposed to be much softer than the $^{48}$Ca core. The very low magnetic moment $\mu(^{55}\mathrm{Ni})=-1.108(20)\,\mu_N$ indicates the impact of M1 excitations between spin-orbit partners across the $N,Z=28$ shell gaps. Our charge-radii results are compared to \textit{ab initio} and nuclear density functional theory calculations, showing good agreement within theoretical uncertainties.