Partial wave analysis in K‐matrix formalism

A description is given of the K‐matrix formalism. The formalism, which is normally applied to two‐body scattering processes, is generalized to production of two‐body channels with finalstate interactions. A multi‐channel treatment of production of resonances has been worked out in the P‐vector approach of Aitchison. An alternative approach, derived from the P‐vector, gives the production amplitude as a product of the T‐matrix for a two‐body system and a vector Q specifying its production. This formulation, called Q‐vector approach here, has also been worked out. Examples of practical importance are given.