The Riemann Surface of a Static Dispersion Model and Regge Trajectories

The S-matrix in the static limit of a dispersion relation is a matrix of a finite order N of meromorphic functions of energy ω in the plane with cuts ( −∞ , − 1] , [+1 , + ∞ ). In the elastic case it reduces to N functions S i ( ω ) connected by the crossing symmetry matrix A. The scattering of a neutral pseodoscalar meson with an arbitrary angular momentum l at a source with spin 1/2 is considered (N=2). The Regge trajectories of this model are explicitly found.