First measurement of the CP-violating phase in B0s→J/ψ( → e+e−)ϕ decays

A flavour-tagged time-dependent angular analysis of B0 s → J/ψφ decays is presented where the J/ψ meson is reconstructed through its decay to an e +e − pair. The analysis uses a sample of pp collision data recorded with the LHCb experiment at centre-of-mass energies of 7 and 8 TeV, corresponding to...

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Detalhes bibliográficos
Autores: LHCb Collaboration, Alfonso Albero, Alejandro, García Moreno, Paula, Garrido Beltrán, Lluís, Gironella Gironell, P., Gomez Fernandez, S., Graugés Pous, Eugeni, Lobo Salvia, A., Mauricio, J., Vazquez Gomez, R., Marin Benito, Carla
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2021
País:España
Recursos:Universidad de Barcelona
Repositório:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/185481
Acesso em linha:https://hdl.handle.net/2445/185481
Access Level:Acceso aberto
Palavra-chave:Hadrons
Gran Col·lisionador d'Hadrons
Física de partícules
Experiments
Large Hadron Collider (France and Switzerland)
Particle physics
Descrição
Resumo:A flavour-tagged time-dependent angular analysis of B0 s → J/ψφ decays is presented where the J/ψ meson is reconstructed through its decay to an e +e − pair. The analysis uses a sample of pp collision data recorded with the LHCb experiment at centre-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3 fb−1 . The CP-violating phase and lifetime parameters of the B0 s system are measured to be φs = 0.00 ± 0.28 ± 0.05 rad, ∆Γs = 0.115 ± 0.045 ± 0.011 ps−1 and Γs = 0.608 ± 0.018 ± 0.011 ps−1 where the first uncertainty is statistical and the second systematic. This is the first time that CP-violating parameters are measured in the B0 s → J/ψφ decay with an e +e − pair in the final state. The results are consistent with previous measurements in other channels and with the Standard Model predictions.