Multichannel phase-equivalent transformation and supersymmetry

A phase-equivalent transformation of local interaction is generalized to the multichannel case in the direct-scattering problem. Generally, the transformation does not change the number of bound states in the system and their energies. For a special choice of the parameters involved, however, the transformation removes one of the bound states and is equivalent to the multichannel supersymmetry transformation recently proposed by J.M. Sparenberg and D. Baye (1997). With the aid of the transformation, it is also possible to add a bound state to the discrete spectrum of the system at a given energy E < 0 if the angular momentum l ≥ 2 in at least one of the coupled channels