  We present a study of associated jpsi + gamma production through double
Pomeron exchange at energies reached at the Fermilab Tevatron and CERN LHC
based on the Ingelman-Schlein model for hard diffractive scattering and the
factorization formalism of nonrelativistic QCD for quarkonia production. We
find that this process (p + pbar \to p + pbar + jpsi + gamma + X) can be used
to probe the gluon content of the Pomeron and study the natrue of hard
diffractive factorization breaking.
