Ib. Khriplovich et al., NATURE OF THE DARWIN-TERM AND (Z-ALPHA)(4)M(3) M-2 CONTRIBUTION TO THE LAMB-SHIFT FOR AN ARBITRARY SPIN OF THE NUCLEUS/, Journal of experimental and theoretical physics, 84(6), 1997, pp. 1054-1057
The contact Darwin term is demonstrated to be of the same origin as th
e spin-orbit interaction. The (Z alpha)(4)m(3)/M-2 correction for the
Lamb shift, generated by the Darwin term is found for an arbitrary non
vanishing spin of the nucleus, both half-integer and integer. There is
also a contribution of the same nature to the nuclear quadrupole mome
nt. (C) 1997 American Institute of Physics.