  The impact of Hartree-Fock correlations on the nuclear momentum distribution
is studied in a fully relativistic one boson exchange model. Hartree-Fock
equations are exactly solved to first order in the coupling constants. The
renormalization of the Dirac spinors in the medium is shown to affect the
momentum distribution, as opposed to what happens in the non-relativistic case.
The unitarity of the model is shown to be preserved by the present
renormalization procedure.
