  We study a significant nuclear suppression of the relative production rates
(p(d)+A)/(p+d(p)) for the Drell-Yan process at large Feynman xF. Since this is
the region of minimal values for the light-front momentum fraction variable x2
in the target nucleus, it is tempting to interpret this as a manifestation of
coherence or of a Color Glass Condensate. We demonstrate, however, that this
suppression mechanism is governed by the energy conservation restrictions in
multiple parton rescatterings in nuclear matter. To eliminate nuclear shadowing
effects coming from the coherence, we calculate nuclear suppression in the
light-cone dipole approach at large dilepton masses and at energy accessible at
FNAL. Our calculations are in a good agreement with data from the E772
experiment. Using the same mechanism we predict also nuclear suppression at
forward rapidities in the RHIC energy range.
