학술논문

Measurement of the τ-→ηπ-π+π-ντ branching fraction and a search for a second-class current in the τ- →η′(958)π-ντ decay
Document Type
article
Source
Physical Review D - Particles, Fields, Gravitation and Cosmology. 77(11)
Subject
Astronomical and Space Sciences
Atomic
Molecular
Nuclear
Particle and Plasma Physics
Quantum Physics
Nuclear & Particles Physics
Language
Abstract
The τ-→ηπ-π+π-ντ decay with the η→γγ mode is studied using 384fb-1 of data collected by the BABAR detector. The branching fraction is measured to be (1.60±0. 05±0.11)×10-4. It is found that τ-→f1(1285)π- ντ→ηπ-π+π-ντ is the dominant decay mode with a branching fraction of (1.11±0.06±0.05)×10-4. The first error on the branching fractions is statistical and the second systematic. Note that no particle identification algorithm is applied to the charged tracks to distinguish pions from kaons. In addition, a 90% confidence level upper limit on the branching fraction of the τ-→η′(958)π-ντ decay is measured to be 7.2×10-6. This last decay proceeds through a second-class current and is expected to be forbidden in the limit of isospin symmetry. © 2008 The American Physical Society.