Evidence for Linear Extrapolations of Baryon-Exchange Trajectories through Particle Mass Spectra

The N_α and Δ_δ Regge-trajectory functions in the scattering region are obtained from analysis of new data on backward π^±p elastic scattering. At small $|u|$, the intercepts and slopes of both trajectories agree with straight-line extrapolations α=a+bu through the baryon masses. In the large $|u|$ region, the trajectories appear to be leveling off.