Measurement of CP violation in B-0 -> J/psi K-S(0) and B-0 -> psi(2S) K-S(0) decays

Journal article

A measurement is presented of decay-time-dependent CP violation in the decays B 0 → J/ψ K S 0 and B 0 → ψ(2S)K S 0 , where the J/ψ is reconstructed from two electrons and the ψ(2S) from two muons. 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 -violation observables are measured to beC(B0→J/ψKS0)=0.12±0.07±0.02,S(B0→J/ψKS0)=0.83±0.08±0.01,C(B0→ψ(2S)KS0)=−0.05±0.10±0.01,S(B0→ψ(2S)KS0)=0.84±0.10±0.01,where C describes CP violation in the direct decay, and S describes CP violation in the interference between the amplitudes for the direct decay and for the decay after B 0 − B¯ 0 oscillation. The first uncertainties are statistical and the second are systematic. The two sets of results are compatible with the previous LHCb measurement using B 0 → J/ψ K S 0 decays, where the J/ψ meson was reconstructed from two muons. The averages of all three sets of LHCb results areC(B0→[cc¯]KS0)=−0.017±0.029,S(B0→[cc¯] KS0)=0.760±0.034,under the assumption that higher-order contributions to the decay amplitudes are negligible. The uncertainties include statistical and systematic contributions.[Figure not available: see fulltext.].

Authors: Aaij, R; Adeva, B; Adinolfi, M; Bjørn, M; Cheung, S

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Springer Verlag
• Journal: Journal of High Energy Physics
• Volume: 2017
• Issue: 170
• Pages: 1-18
• Publication date: 2017-11-27
• Acceptance date: 2017-11-12
• DOI: 10.1007/JHEP11(2017)170
• EISSN: 1029-8479
• ISSN: 1126-6708
• Keywords: B physics; CP violation; Hadron-Hadron scattering (experiments); CKM angle beta; Journal Article; Flavor physics