Spin-orbit splittings of neutron states in $N = 20$ isotones from covariant density functionals and their extensions

摘要

Spin-orbit splitting is an essential ingredient for our understanding of theshell structure in nuclei. One of the most important advantages of relativisticmean-field (RMF) models in nuclear physics is the fact that the largespin-orbit (SO) potential emerges automatically from the inclusion ofLorentz-scalar and -vector potentials in the Dirac equation. It is therefore ofgreat importance to compare the results of such models with experimental data.We investigate the size of $2p$ and $1f$ splittings for the isotone chain$^{40}$Ca, $^{38}$Ar, $^{36}$S, and $^{34}$Si in the framework of variousrelativistic and nonrelativistic density functionals. They are compared withthe results of nonrelativistic models and with recent experimental data.