Relativistic one-pion-exchange potentials

We compare three different types of relativistic two-body equations, namely the Blankenbecler-Sugar equation, the Gross equation, and an equation derived from relativistic three-body equations. Regarding the one-boson-exchange, the corresponding potentials coincide on mass shell but differ off shell. The potential connected with the three-body equation even shows some cuts in the momentum plane. We analyze the differences for the example of the one-pion-exchange calculating half-off-shell functions and phase shifts. We also include strong NN form factors and discuss the influence of some of their parametrizations on the phase shifts.