Relativity and spin-orbit interaction in nuclei

It is shown that the observed spin-orbit splittings in the atomic nuclei may be explained theoretically if one takes into account the relativistic character of the nucleon motion in the bound many-nucleon system. The relativistic corrections were obtained from the approximately relativistically invariant (to within terms in v2/c2) Breit-type equation for two nucleons. Two-particle interactions were taken in the form of one-boson-exchange potentials which reproduce well the nucleon-nucleon scattering data and which include pseudoscalar, scalar and vector mesons and resonances. The calculations of the doublet splittings of different single-particle levels in 41Ca and 209Pb were carried out, the values of the nuclear average field being calculated as well. Agreement with experiment is reasonably satisfactory.