ν(τ) Helicity from h(±) Energy Correlations

Abstract

We report a measurement of the magnitude of the ν(τ) helicity from τ-pair events taken with the CLEO detector at the CESR electron-positron storage ring. Events in which each τ undergoes the decay τ→hν, with h a charged pion or kaon, are analyzed for energy correlations between the daughter hadrons, yielding |ξ(h)| = 1.03±0.06±0.04, with the first error statistical and the second systematic.