Hadronic decays of the tau lepton: tau ---> pi pi pi nu_tau within resonance chiral theory

DANIEL GOMEZ DUMM; ANTONIO PICH; JORGE PORTOLES

Bari

Workshop; International Workshop on Quantum Chromodynamics: QCD@Work 2005; 2005

Tau decays into hadrons foresee the study of the hadronization of vector and axial-vector QCD currents, yielding relevant information on the dynamics of the resonances entering into the processes. We analyse tau -> pi pi pi nu_tau  decays within the framework of the Resonance Chiral Theory, comparing this theoretical scheme with the experimental data, namely ALEPH spectral function and branching ratio. Hence we get values for the mass and on-shell width of the a1(1260) resonance, and provide the structure functions that have been measured by OPAL and CLEO-II.