The Okubo-Zweig-Iizuka (OZI) rule is prominent in hadronic phenomena only b
ecause OZI violation is typically an order of magnitude smaller than expect
ed from large N-c arguments. With its standard (3)p(o) pair creation operat
or for hadronic decays by flux tube breaking, the quark model respects the
OZI rule at the tree level and exhibits the cancellations between OZI-viola
ting meson loop diagrams required for this dramatic suppression. However. i
f the quark model explanation for these cancellations is correct, then OZI
violation would be expected to be large in the nonet with the same quantum
numbers as the pair creation operator: the 0(++) mesons, Experiment is curr
ently unable to identify these mesons, but we report here on a lattice QCD
calculation which confirms that the OZI rule arises from QCD in the vector
and axial vector mesons as observed, and finds a large violation of the rul
e in the scalar mesons as anticipated by the quark model. In view of this r
esult, we make some remarks on possible connections between the P-3(o) pair
creation model, scalar mesons, and the U-A(1) anomaly responsible for the
large OZI violation which drives the eta' mass.