Abstract
The production of a resonance in a collision is studied from a semiphenomenological point of view as a rescattering effect. The framework is an integral equation of the Muskhelishvili-Omnès type, with the rescattering parameters (e.g., phase shift) assumed known. In particular, the possibility of structure (e.g., zeros) in the line shape is investigated. Coupled singular equations are also examined, and an explicit solution is obtained in a particular case.