Observation of Υ(4S) Decays to π+π−Υ(1S) and π+π−Υ(2S)
We present the first measurement of Υ ( 4 S ) decays to π + π − Υ ( 1 S ) and π + π − Υ ( 2 S ) based on a sample of 230 × 10 6 Υ ( 4 S ) mesons collected with the BABAR detector. We measure the product branching fractions B ( Υ ( 4 S ) → π + π − Υ ( 1 S ) ) × B ( Υ ( 1 S ) → μ + μ − ) = ( 2.23 ± 0....
| Autores: | , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2006 |
| País: | España |
| Institución: | Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya) |
| Repositorio: | Recercat. Dipósit de la Recerca de Catalunya |
| OAI Identifier: | oai:recercat.cat:2445/140512 |
| Acceso en línea: | https://hdl.handle.net/2445/140512 |
| Access Level: | acceso abierto |
| Palabra clave: | Física de partícules Experiments Particle physics |
| Sumario: | We present the first measurement of Υ ( 4 S ) decays to π + π − Υ ( 1 S ) and π + π − Υ ( 2 S ) based on a sample of 230 × 10 6 Υ ( 4 S ) mesons collected with the BABAR detector. We measure the product branching fractions B ( Υ ( 4 S ) → π + π − Υ ( 1 S ) ) × B ( Υ ( 1 S ) → μ + μ − ) = ( 2.23 ± 0.25 stat ± 0.27 syst ) × 10 − 6 and B ( Υ ( 4 S ) → π + π − Υ ( 2 S ) ) × B ( Υ ( 2 S ) → μ + μ − ) = ( 1.69 ± 0.26 stat ± 0.20 syst ) × 10 − 6 , from which we derive the partial widths Γ ( Υ ( 4 S ) → π + π − Υ ( 1 S ) ) = ( 1.8 ± 0.4 ) keV and Γ ( Υ ( 4 S ) → π + π − Υ ( 2 S ) ) = ( 2.7 ± 0.8 ) keV . |
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