Spin-orbit splitting in low-j neutron orbits and proton densities in the nuclear interior

Todd, B. G.; Piekarewicz, J.; Cottle, P. D.

Spin-orbit splitting in low-j neutron orbits and proton densities in the nuclear interior

Authors

Todd, B. G.

Piekarewicz, J.

Cottle, P. D.

Description

On the basis of relativistic mean field calculations, we predict that the spin-orbit splitting of $p_{3/2}$ and $p_{1/2}$ neutron orbits depends sensitively on the magnitude of the proton density near the center of the nucleus, and in particular on the occupation of $s_{1/2}$ proton orbits. We focus on two exotic nuclei, $^{46}$Ar and $^{206}$Hg, in which the presence of a pair of $s_{1/2}$ proton holes is predicted to cause the splitting between the $p_{3/2}$ and $p_{1/2}$ neutron orbits near the Fermi surface to be much smaller than in the nearby doubly-magic nuclei $^{48}$Ca and $^{208}$Pb. We note that these two exotic nuclei depart from the long-standing paradigm of a central potential proportional to the ground state baryon density and a spin-orbit potential proportional to the derivative of the central potential.
4 pages, 4 figures