Abstract: We report measurements of the inclusive reaction, , in events where either or both the beam-like final-state baryons were detected in Roman-pot spectrometers and the central system was detected in the UA2 calorimeter. A Double-Pomeron-Exchange analysis of these data and single diffractive data from the same experiment demonstrates that, for central masses of a few GeV, the extracted Pomeron-Pomeron total cross section exhibits an enhancement which exceeds factorization expectations by an order-of-magnitude. This may be a signature for glueball production and provides interesting arguments for a new decisive experiment at RHIC.