Mass dependence of wightman function and light front singularity
  The Wightman function for a massive free scalar field is studied within the light front formulation, while a special attention is paid to its mass dependence. The long lasting inconsistency is successfully solved by means of the novel Fourier representation for scalar fields. The new interpretation of the light front singularities as the high momentum phenomena is presented and adequate regularizations are implemented. 
Jerzy A. Przeszowski and Jan Zochowski