Linearly rising Regge trajectories and bag and string models for hadrons

Experimental evidence conclusively establishing rising Regge trajectories is strongly suggestive of a universal string or vortex connecting quarks. We perform fits incorporating the latest data (highest-spin states) and show that apparent deviations from a universal, linear Regge trajectory can be completely explained in terms of nonzero masses for the quarks at the end of the string. We advocate continued, detailed study of Regge trajectories and their high-spin members as one of the best laboratories for exploring the nature of quark confinement in QCD.