Meson decay in the Fock-Tani Formalism
  The Fock-Tani formalism is a first principle method to obtain effective interactions from microscopic Hamiltonians. Usually this formalism was applied to scattering, here we introduced it to calculate partial decay widths for mesons. 
D.T. da Silva, M. L. L. da Silva, D. Hadjimichef, C. A. Z.   Vasconcellos