Abstract
The evolution of neutron single-particle spectra of isotones with \(N=32\) and \(34\) new magic neutron numbers in the region \(16\leq Z\leq 32\) was calculated in the dispersive optical model. It was shown that the minimum of the difference between the Fermi energy and the half-sum of the energy levels of the last predominantly occupied state and the first predominately unoccupied state is achieved in the magic isotones with \(N=32\) and \(34\) . The calculated root-mean-square radius of the neutron halo-like state \(2p_{3/2}\) in the double magic \({}^{52}\) Ca nucleus exceeded the radius of the underlying \(1f_{7/2}\) state by 0.8 fm. It is consistent with the recent experimental data and theoretical predictions that explain ‘‘unexpectedly’’ large root-mean-square charge radius of this nucleus.
