Observation of B¯→D(*) π+π−ℓ−ν¯ Decays in e+e− Collisions at the Υ(4S) Resonance
We report on measurements of the decays of ¯ B mesons into the semileptonic final states ¯ B → D ( * ) π + π − ℓ − ¯ ν , where D ( * ) represents a D or D ∗ meson and ℓ − is an electron or a muon. These measurements are based on 471 × 10 6 B ¯ B pairs recorded with the BABAR detector at the SLAC asy...
| Autores: | , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2016 |
| 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:2445/119383 |
| Acceso en línea: | https://hdl.handle.net/2445/119383 |
| Access Level: | acceso abierto |
| Palabra clave: | Partícules (Física nuclear) Mesons (Física nuclear) Particles (Nuclear physics) Mesons (Nuclear physics) |
| Sumario: | We report on measurements of the decays of ¯ B mesons into the semileptonic final states ¯ B → D ( * ) π + π − ℓ − ¯ ν , where D ( * ) represents a D or D ∗ meson and ℓ − is an electron or a muon. These measurements are based on 471 × 10 6 B ¯ B pairs recorded with the BABAR detector at the SLAC asymmetric B factory PEP-II. We determine the branching fraction ratios R ( * ) π + π − = B ( ¯ B → D ( * ) π + π − ℓ − ¯ ν ) / B ( ¯ B → D ( * ) ℓ − ¯ ν ) using events in which the second B meson is fully reconstructed. We find R π + π − = 0.067 ± 0.010 ± 0.008 and R ∗ π + π − = 0.019 ± 0.005 ± 0.004 , where the first uncertainty is statistical and the second is systematic. Based on these results and assuming isospin invariance, we estimate that ¯ B → D ( * ) π π ℓ − ¯ ν decays, where π denotes either a π ± and π 0 meson, account for up to half the difference between the measured inclusive semileptonic branching fraction to charm hadrons and the corresponding sum of previously measured exclusive branching fractions. |
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