Scattering problem for relativistic systems with a fixed particle number in the light-front dynamics

Scattering problem is formulated for a system with a fixed particle number in the framework of the light-front dynamics that is considered as a limit of the instant dynamics at infinitely large momentum. Properties of states with spin are considered. The partial wave expansion method is formulated for the scattering amplitudes in the light-front dynamics. A possible form of the phenomenological potentials in the equations for the scattering matrix, consistent with the relativistic invariance, is discussed. Equations for the scattering matrix in relativistic two- and three-particle systems are formulated