Inelastic diffraction data and the effective Pomeron trajectory

Abstract

A further analysis of inelastic diffraction data at the ISR and SPS-Collider confirms the relatively flat s-independent pomeron trajectory in the high-|t| domain, 1-2 GeV^2, reported earlier by the UA8 Collaboration. At |t| = 1.5 GeV^2, alpha = 0.92 +/- 0.03 is in agreement with the trajectories found in diffractive photoproduction of vector mesons at HERA. This suggests a universal fixed Pomeron trajectory at high-|t|. We also show that a triple-Regge Pomeron-exchange parametrization fit to the data requires an s-dependent (effective) Pomeron trajectory intercept, alpha(0), which decreases with increasing s, as expected from unitarization (multi-Pomeron-exchange) calculations. alpha(0) = 1.10 at the lowest ISR energy, 1.03 at the SPS-Collider and perhaps smaller at the Tevatron.