Feshbach resonance: a one dimensional example
  We present a simple one-dimensional example of a spin 1/2 particle submitted to a delta-type potential which interacs differently with the two components of the wavefunction and to an external magnetic field. It has two coupled channels, admits a closed solution and features the Feshbach resonance phenomenon by proper tunning of the magnetic field. 
Josep Taron
physics.atom-ph cond-mat.quant-gas quant-ph