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.

(2025). First Evidence for Direct CP Violation in Beauty to Charmonium Decays [journal article - articolo]. In PHYSICAL REVIEW LETTERS. Retrieved from https://hdl.handle.net/10446/311531

First Evidence for Direct CP Violation in Beauty to Charmonium Decays

Lupato A.;Redi F.;
2025-01-01

Abstract

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.
articolo
2025
Aaij, R.; Abdelmotteleb, A. S. W.; Abellan Beteta, C.; Abudinen, F.; Ackernley, T.; Adefisoye, A. A.; Adeva, B.; Adinolfi, M.; Adlarson, P.; Agapopoul...espandi
(2025). First Evidence for Direct CP Violation in Beauty to Charmonium Decays [journal article - articolo]. In PHYSICAL REVIEW LETTERS. Retrieved from https://hdl.handle.net/10446/311531
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10446/311531
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