Solutions of the Bethe-Salpeter Equation in Minkowski space: a   comparative study
  The Bethe-Salpeter Equation for a two-scalar, S-wave bound system, interacting through a massive scalar, is investigated within the ladder approximation. By assuming a Nakanishi integral representation of the Bethe-Salpeter amplitude, one can deduce new integral equations that can be solved and quantitatively studied, overcoming the analytic difficulties of the Minkowski space.   Finally, it is shown that the Light-front distributions of the valence state, directly obtained from the Bethe-Salpeter amplitude, open an effective window for studying the two-body dynamics. 
Giovanni Salme` (INFN - Rome), Tobias Frederico (ITA - S. Jose' dos   Campos) and Michele Viviani (INFN - Pisa)
hep-ph cond-mat.str-el nucl-th