If nucleon anti-shadowing in photon and lepton quarkonium (QQBAR)v pro
duction is the result of the coherent interaction of the quarkonium (Q
QBAR) v systems coupled to the photon in nuclear matter, the quarkoniu
m nucleon elastic amplitude must have a large positive real past in th
e forward direction. This can be achieved by requiring that at high en
ergy the cross-sections become beam independent, sigma(NN) congruent-t
o Q(VN) and, in particular, sigma4N congruent-to sigma(gammaN) congrue
nt-to sigma((ttBAR))N).