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
The τ − → η π − π + π − ν τ decay with the η → γ γ mode is studied using 384 fb − 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 − → f 1 ( 1285 ) π − ν τ → η π − π + π − ν τ is the dominant decay mode with...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2008 |
| País: | España |
| Institución: | Universidad de Barcelona |
| Repositorio: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/131523 |
| Acceso en línea: | https://hdl.handle.net/2445/131523 |
| Access Level: | acceso abierto |
| Palabra clave: | Física de partícules Experiments Particle physics |
| Sumario: | The τ − → η π − π + π − ν τ decay with the η → γ γ mode is studied using 384 fb − 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 − → f 1 ( 1285 ) π − ν τ → η π − π + π − ν τ 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 − ν τ 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. |
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