Reduction of the spin-orbit potential in light drip-line nuclei

The isospin dependence of the spin-orbit interaction in light neutron rich nuclei is investigated in the framework of relativistic mean field theory. The magnitude of the spin-orbit potential is considerably reduced in drip line nuclei, resulting in smaller energy splittings between spin-orbit partners. The effect does not depend on the parametrization of the effective Lagrangian. The results are compared with corresponding calculations in the non-relativistic Skyrme model.