51000 TAU-DECAYS

An analysis has been made of 51 000 K-→π-π-π+ decays in flight in the Berkeley 25-in. hydrogen bubble chamber. After corrections for detection efficiency and Coulomb interactions, the projections of the pion spectra have been fitted with expansions in the Dalitz variables X and Y. In addition, maximum-likelihood fits to the entire Dalitz plot have been made. The decay distribution is well described by 1+aY, where the slope a=0.247±0.009. Comparison of this slope with that derived from a world compilation of 28 000 τ+ decays shows no evidence for CP violation. An isospin analysis of the rates and slopes of τ, τ′, and of K20→3π decays, requires, in addition to the dominant ΔI=12 amplitude, ΔI=32 amplitudes into both I=1 and I=2 three-pion final states. No detectable ΔI=52 or ΔI=72 amplitudes are required. © 1969 The American Physical Society.