First Evidence for Direct CP Violation in Beauty to Charmonium Decays
The CP asymmetry and branching fraction of the Cabibbo-Kobayashi-Maskawa-suppressed decay B+→J/ψπ+ are precisely measured relative to the favored decay B+→J/ψK+ using a sample of proton-proton collision data corresponding to an integrated luminosity of 5.4 fb-1 recorded at a center-of-mass energy of...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2024 |
| País: | España |
| Institución: | Universitat Ramon Llull (URL) |
| Repositorio: | DAU Arxiu Digital de la Universitat Ramon Llull |
| OAI Identifier: | oai:dau.url.edu:20.500.14342/5819 |
| Acceso en línea: | http://hdl.handle.net/20.500.14342/5819 https://doi.org/10.1103/PhysRevLett.134.101801 |
| Access Level: | acceso abierto |
| Palabra clave: | Cabibbo-Kobayashi-Maskawa matrix Bottom mesons charm quark CP violation Discrete symmetries Hadron colliders Gran col·lisionador d'hadrons (França i Suïssa) 53 530.1 539 |
| Sumario: | The CP asymmetry and branching fraction of the Cabibbo-Kobayashi-Maskawa-suppressed decay B+→J/ψπ+ are precisely measured relative to the favored decay B+→J/ψK+ using a sample of proton-proton collision data corresponding to an integrated luminosity of 5.4 fb-1 recorded at a center-of-mass energy of 13 TeV during 2016-2018. The results of the CP asymmetry difference and branching fraction ratio are ΔACPACP(B+→J/ψπ+)-ACP(B+→J/ψK+)=(1.29±0.49±0.08)×10-2, Rπ/K[B(B+→J/ψπ+)/B(B+→J/ψK+)]=(3.852±0.022±0.018)×10-2, where the first uncertainties are statistical and the second are systematic. A combination with previous LHCb results based on data collected at 7 and 8 TeV in 2011 and 2012 yields ΔACP=(1.42±0.43±0.08)×10-2 and Rπ/K=(3.846±0.018±0.018)×10-2. The combined ΔACP value deviates from zero by 3.2 standard deviations, providing the first evidence for direct CP violation in the amplitudes of beauty decays to charmonium final states. |
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