Structure and decay constant of the \rho meson with Bethe-Salpeter   equation
  In this article, we study the structure of the \rho meson in the framework of the coupled rainbow Schwinger-Dyson equation and ladder   Bethe-Salpeter equation with a confining effective potential. The u and d quark propagators get significantly modified, the mass poles are absent in the timelike region, which implements confinement naturally. The Bethe-Salpeter amplitudes of the \rho meson center around zero momentum and extend to the energy scale about $q^2=1GeV^2$, which happens to be the energy scale of chiral symmetry breaking, strong interactions in the infrared region result in bound state. The numerical results of the mass and decay constant of the \rho meson are in agreement with the experimental data. 
Z. G. Wang, S. L. Wan