Charge radii of ${}^{55,56}$Ni reveal a surprisingly similar behavior at $N=28$ in Ca and Ni isotopes

F. Sommer, K. König, D. M. Rossi +24

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…