Study of tau decays to six pions and a neutrino

Abstract

The tau decays to six-pion final states have been studied with the CLEO detector at the Cornell Electron Storage Ring. The measured branching fractions are B(tau (-) --> 2 pi (-)pi (-)3 pi (0)nu (tau)) = (2.2 +/- 0.3 +/- 0.4) X 10(-4) and B(tau (-) --> 3 pi (-)2 pi (+)pi (0)nu (tau)) = (1.7 +/- 0.7 +/- 0.2) X 10(-4). A search for substructure in these decays shows that they are saturated by intermediate states with eta or omega mesons. We present the first observation of the decay tau (-) --> 2 pi (-)pi (+)omega nu (tau) and the branching fraction is measured to be (1.2 +/- 0.2 +/- 0.1) x 10(-4). The measured branching fractions are in good agreement with the isospin expectations but somewhat below the conserved-vector-current predictions.