Analytic properties of the inclusive cross section in the scattering angle in a class of ladder models with dynamical symmetry

An investigation is made into the analytic properties of the single-particle inclusive cross section in the variable $\cos\theta$ ($\theta$ is the c. m. s. scattering angle) for ladder models with the dynamical symmetry $O(4,1)$. The analyticity domain is a plane with cuts along the real axis. The position of the singularities nearest the origin agrees with the conjecture made by Logunov and Mestvirishvili [2].