Solving a coupled-channels scattering problem by adding confining potentials

A new method to obtain both the wave function and S matrix for coupled-channels scattering problems is presented. The method is characterized by the introduction of a real confining potential acting in the external region, which enables one to solve the problem using virtually only the bound-state solutions. The asymptotic behavior of the continuum state is guaranteed with a single-channel Green's function. The accuracy and simplicity of the method are demonstrated on the two examples of an exactly solvable two-channel potential and the nucleon–nucleon scattering.