Overlapping channels and multichannel phenomena

The problem of multichannel scattering is studied in the framework of potential theory. Some of the difficulties that arise in highenergy physics due to the overlapping of channels, are simulated here. The problem is treated in such a way, that the different channels are separated and identifiable in the initial, final and intermediate states. A basis system is constructed, which serves this purpose better than the usual plane-wave states of the different channels. The procedure used also clarifies the validity of treating particles as elementary in some approximation when they may actually be composite. The relevance to strong-interaction physics is discussed in the conclusion