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

A flavour-tagged time-dependent angular analysis of B0s→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\,Te V, corresponding to an...

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Bibliographic Details
Main Authors: Aaij, R., Abellán Beteta, C., Ackernley, T., Adeva, B., Adinolfi, M., Afsharnia, H., Aidala, C. A., Aiola, S., Ajaltouni, Z., Akar, S., Albrecht, J., Alessio, F., Alexander, M., Alfonso Albero, A., Aliouche, Z., Alkhazov, G., Alvarez Cartelle, P., Amato, S., Amhis, Y., An, L.
Other Authors: Massachusetts Institute of Technology. Department of Physics
Format: Article
Language:English
Published: Springer Berlin Heidelberg 2021
Online Access:https://hdl.handle.net/1721.1/138229
Description
Summary:A flavour-tagged time-dependent angular analysis of B0s→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\,Te V, corresponding to an integrated luminosity of 3\,fb−1. The CP-violating phase and lifetime parameters of the B0s system are measured to be ϕs=0.00±0.28±0.07\,rad, ΔΓs=0.115±0.045±0.011\,ps−1 and Γs=0.608±0.018±0.012\,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 B0s→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.