Effective potential for relativistic scattering
  We consider quantum inverse scattering with singular potentials and calculate the Sine-Gordon model effective potential in the laboratory and centre-of-mass frames. The effective potentials are frame dependent but closely resemble the zero-momentum potential of the equivalent Ruijsenaars-Schneider model. 
Mahmut Elbistan, Pengming Zhang, Janos Balog
nucl-th hep-th