Effect of color screening on heavy quarkonia Regge trajectories

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.