  The effect of the center of mass motion on the high-momentum distributions of
correlated nucleon pairs is studied by solving the Bethe-Goldstone equation in
nuclear matter with the Granada nucleon-nucleon potential. We show that this
coarse-grained potential reduces the problem to an algebraic linear system of
five (ten) equations for uncoupled (coupled) partial waves that can be easily
solved. The corresponding relative wave functions of correlated pn, pp and nn
pairs are computed for different values of their CM momentum. We find that the
pn pairs dominate the high-momentum tail of the relative momentum distribution,
and that this only depends marginally on center of mass momentum. Our results
provide further justification and agreement for the factorization approximation
commonly used in the literature. This approximation assumes that the momentum
distribution of nucleon pairs can be factorized as the product of the center of
mass momentum distribution and the relative momentum distribution.
