On Form Factor of the Relativistic Two-Particle System in the Relativistic Quasipotential Approach

For the cases of scalar and vector currents, new covariant expressions have been found for the components of the elastic form factor for a bound system of two relativistic spinless particles of arbitrary masses as functions of the invariant variable. Delta(2)(P,Q), which is the square of the momentum-transfer vector in the Lobachevsky space. The present consideration has been performed within the relativistic quasipotential approach based on the covariant Hamiltonian formulation of quantum field theory by going over to the three dimensional relativistic configuration representation.