“…The isovector contribution is, of course, also responsible for the difference between the effective proton and neutron single-particle potentials, while the radial (density) profiles depend on the shell structure of occupied orbitals in the self-consistent solution for a particular nucleus. In this respect, especially interesting is the case of 34 Si, for which a possible central depletion of the proton density distribution has been analysed using a variety of theoretical approaches [26,27], and experimental constraints on the strength of the two-body spin-orbit interaction have been reported [15,28]. For the effective interaction DD-MEδ that explicitly includes contributions from both ρ and δ meson exchange in the direct term, the isovector channel of the spin-orbit potential is enhanced when compared to DD-ME2, although in both models the total isovector part of the spin-orbit potential is an order of magnitude weaker than the isoscalar contribution [20].…”