Using an unquenched lattice potential to calculate the spectrum of a bottom
onium-like system, we demonstrate numerically that the effect of pair creat
ion is to produce termination of the real part of hadronic Regge trajectori
es, in contrast to the Veneziano model and the vast majority of phenomenolo
gical generalizations. Termination of the real part of Regge trajectories m
ay have significant experimental consequences. (C) 1999 Elsevier Science B.
V. All rights reserved.