Measurement of the Ratio of Branching Fractions B(¯B0→D*+τ−¯ντ)/B(¯B0→D*+μ−¯νμ)
The branching fraction ratio R ( D ∗ ) ≡ B ( ¯ B 0 → D * + τ − ¯ ν τ ) / B ( ¯ B 0 → D * + μ − ¯ ν μ ) is measured using a sample of proton-proton collision data corresponding to 3.0 fb − 1 of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identifie...
| Autores: | , , , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2015 |
| País: | España |
| Institución: | Universidad de Barcelona |
| Repositorio: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/132872 |
| Acceso en línea: | https://hdl.handle.net/2445/132872 |
| Access Level: | acceso abierto |
| Palabra clave: | Física de partícules Experiments Particle physics |
| Sumario: | The branching fraction ratio R ( D ∗ ) ≡ B ( ¯ B 0 → D * + τ − ¯ ν τ ) / B ( ¯ B 0 → D * + μ − ¯ ν μ ) is measured using a sample of proton-proton collision data corresponding to 3.0 fb − 1 of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode τ − → μ − ¯ ν μ ν τ . The semitauonic decay is sensitive to contributions from non-standard-model particles that preferentially couple to the third generation of fermions, in particular, Higgs-like charged scalars. A multidimensional fit to kinematic distributions of the candidate ¯ B 0 decays gives R ( D ∗ ) = 0.336 ± 0.027 ( stat ) ± 0.030 ( syst ) . This result, which is the first measurement of this quantity at a hadron collider, is 2.1 standard deviations larger than the value expected from lepton universality in the standard model. |
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