ANGULAR-DISTRIBUTIONS IN SEMILEPTONIC TAU DECAYS

A complete description of angular distributions in terms of four structure functions is given for the three pion system in a spin one state resulting from the decay of polarized tau's. Of particular importance is the case where the tau's are produced in e+ e-annihilation and the tau rest frame cannot be reconstructed. It will be demonstrated that the structure functions can be measured even in this case, even with unpolarized tau's. The importance of the angle-psi, which denotes the angle between the direction of the laboratory and the tau as seen from the three pion rest frame is emphasized. Predictions for the structure functions based on a specific model for the hadronic current will be presented.