Four-pion production in τ decays and e+e- annihilation:: An update

An improved description of four-pion production in electron-positron annihilation and in tau-lepton decays is presented. The model amplitude is fitted to recent data from BABAR which cover a wide energy range and which were obtained exploiting the radiative return. Predicting tau-decay distributions from e(+)e(-) data and comparing these predictions with ALEPH and CLEO results, the validity of isospin symmetry is confirmed within the present experimental errors. A good description of two- and three-pion subdistributions is obtained. Special emphasis is put on the predictions for omega pi(->pi(+)pi(-)pi(0)) in e(+)e(-) annihilation and in tau decay. The model amplitude is implemented in the Monte Carlo generator PHOKHARA.