Multichannel coupling with supersymmetric quantum mechanics and   exactly-solvable model for Feshbach resonance
  A new type of supersymmetric transformations of the coupled-channel radial Schroedinger equation is introduced, which do not conserve the vanishing behavior of solutions at the origin. Contrary to usual transformations, these ``non-conservative'' transformations allow, in the presence of thresholds, the construction of potentials with coupled scattering matrices from uncoupled potentials. As an example, an exactly-solvable potential matrix is obtained which provides a very simple model of Feshbach-resonance phenomenon. 
J.-M. Sparenberg, B. F. Samsonov, F. Foucart and D. Baye