S-matrix engineering

The efficiency of all fusion reactions is characterized by the analytic structure of the scattering (S)-matrix, whose Riemann surface becomes very intricate in the case of scattering from a molecule into nuclear threshold resonances. This is necessarily a multi-channel problem involving a logarithmic branching structure of the S-matrix and shadow poles on the non-physical sheets. Such topology endows the S-matrix with sensitivity to applied optical fields. In general, the laser is able to affect analytic properties of the scattering amplitudes, thereby altering fusion cross sections without requiring plasma ignition.