Heavy quarkonium production in double pomeron exchange processes in perturbative QCD

We calculate the heavy quarkonium production in double pomeron exchange processes in perturbative QCD by using two-gluon exchange model. For the P-wave chi (J) productions, we find chi (1) and chi (2) production amplitudes which vanish in the forward scattering limit. We also calculate direct J/psi(gamma) + gamma production in the same approach, and these direct contributions are much smaller than the feeddown contributions from the P-wave states. (C) 2001 Published by Elsevier Science B.V.