Pole Approximation for the pion eletromagnetic form factor within   light-front dynamics
  We carefully investigate the reliability of the propagator Pole Approximation, i.e, the approximation of retaining only the propagator in the evaluation of the Mandelstam covariant expression for the eletromagnetic current of the pion. Different frames are analyzed, in order to find the most suitable one for calculating the pion form factor within the proposed approximation. It turns out that approximation is more accurate in the frame where q^+ is maximal. The relevance of the Pole Approximation is briefly discussed in view of calculations of hadrons factors basead wave functions generate by dynamical models. 
J.P.B.C. de Melo (1,2), J. S. Veiga (1), T. Frederico, (3), E. Pace   (4,5), G. Salme (5,6), ((1) CETEC, Universidade Cruzei...