The ρ-meson in an effective description of low-energy electro-weak transitions of hadrons

Starting with the general principles of global and local symmetries, an effective lagrangian is developed to describe consistently low-energy electro-weak transitions in the system that incorporates nucleons, pions , rho-mesons, photons and W-+/--, Z(0)-bosons. As the effective lagrangian is essentially nonlinear in the pion field, we sum up properly emerged infinite series in the pion field so that no divergences occur in the course of calculations. The developed approach proves to be relevant to consider low-energy electro-weak interactions among rho-mesons, nucleons, and pions.