  A renormalizable non-Abelian theory of strong interactions of pions, mediated
by rho-mesons, is formulated at tree- and at one-loop level in perturbation
theory. Hadron masses are generated through spontaneous symmetry breaking using
the Higgs mechanism. Quantization and gauge fixing is achieved using the
generalized class of $R_\xi$ gauges. As an application of this theory,
pion-pion scattering lengths are obtained at tree-level in good agreement with
data.
