Hadronic and radiative decays of the tau lepton

This PhD thesis studies some hadronic and radiative decays of the tau lepton using a Chiral Lagrangian including resonance fields. After a theoretical introduction, the decays to the $(\pi \pi \pi {)}^{-}$, $(KK\pi {)}^{-}$ and ${\eta }^{(\mathrm{\prime })}{\pi }^{-}{\pi }^0$ hadronic states and $\tau \to (\pi/K)^- \gamma \nu_tau$ are analysed. Some material, which was not included in the corresponding references, is also discussed: The structure functions analysis for the 3 pion modes, the differential decay width as a function of the two-particle invariant masses in the considered three-meson modes and a simplified study of the $\tau \to$\eta^{(\prime)} \pi^- \pi^0 \nu_tau$ processes within a single-angle mixing scheme for the $\eta$ and ${\eta }^{\mathrm{\prime }}$ mesons.