A crossing-symmetric Regge-pole model of the generalized interference type is discussed. The model consists of a sum of infinitely many Regge poles in each channel, corresponding to a leading Regge trajectory and its parallel daughters. All the usual requirements are satisfied by the Regge residues, and nonlinear trajections can be introduced without difficulty. At the expense of a loss of physical interpretation, the double-counting problem can be eliminated by identifying the Schmid loops with the direct-channel resonances.

• Received 14 July 1969

DOI:https://doi.org/10.1103/PhysRev.188.2154