Inelastic diffraction data and the effective Pomeron trajectory

A further analysis of inelastic diffraction data at the ISR and SPS-Collide r confirms the relatively flat s-independent Pomeron trajectory in the high -\t\ domain, 1 < \t\ < 2 GeV2, reported earlier by the UA8 Collaboration. A t \t\ = 1.5 GeV2 alpha = 0.92 +/- 0.03 is in agreement with the trajectorie s found in diffractive photoproduction of vector mesons at HERA. This sugge sts a universal fixed Pomeron trajectory at high-\t\. We also show that a t riple-Regge Pomeron-exchange parametrization fit to the data requires an s- dependent (effective) Pomeron trajectory intercept, alpha(0), which decreas es with increasing s, as expected from unitarization (multi-Pomeron-exchang e) calculations. alpha(0) = 1.10 at the lowest ISR energy, 1.03 at the SPS- Collider and perhaps smaller at the Tevatron. (C) 2000 Elsevier Science B.V . All rights reserved.