First Observation of τ→3πην_τ and τ→ f₁πν_τ Decays

Authors

T. Bergfeld, University of Illinois - Champaign-Urbana
Kenneth A. Bloom, University of Nebraska-LincolnFollow
CLEO Collaboration

Date of this Version

9-29-1997

Comments

Published by American Physical Society. Phys. Rev. Lett. 79, 2406 (1997). Permission to use. http://prl.aps.org/. Copyright © 1997 American Physical Society.

Abstract

We have observed new channels for τ decays with an η in the final state. We study 3-prong tau decays, using the η →γγ and η → 3π ⁰ decay modes and 1-prong decays with two π ⁰’s using the η →γγ channel. The measured branching fractions are B(τ^- → π^-π^-π⁺ην_τ) = (3. _-0.5^+0.6 ± 0.6) X 10^-4 and B(τ^- → π^-2π ⁰ην_τ) = (1.4 ± 0.6 ± 0.3) X 10^-4. We observe clear evidence for f₁ → ηππ substructure and measure B(τ^- → f₁ π^-ν_τ) = (5.8_-1.3^+1.4 ± 1.8) X 10^-4. We have also searched for η′(958) production and obtain 90% C.L. upper limits B(τ^- → π^{-τ) < 7.4 X 10-5 and B(τ- → π-3π 0 η′ν_τ) , 8.0 X 10-5.}