In:
Journal of High Energy Physics, Springer Science and Business Media LLC, Vol. 2017, No. 11 ( 2017-11)
Abstract:
A measurement is presented of decay-time-dependent CP violation in the decays B 0 → J / ψ K S 0 and B 0 → ψ (2 S ) K S 0 , where the J / ψ is reconstructed from two electrons and the ψ (2 S ) 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 be $$ \begin{array}{l}C\left({B}^0\to J/\psi \kern0.5em {K}_{\mathrm{S}}^0\right)=0.12\pm 0.07\pm 0.02,\\ {}S\left({B}^0\to J/\psi \kern0.5em {K}_{\mathrm{S}}^0\right)=0.83\pm 0.08\pm 0.01,\\ {}C\left({B}^0\to \psi (2S){K}_{\mathrm{S}}^0\right)=-0.05\pm 0.10\pm 0.01,\\ {}S\left({B}^0\to \psi (2S){K}_{\mathrm{S}}^0\right)=0.84\pm 0.10\pm 0.01,\end{array} $$ C B 0 → J / ψ K S 0 = 0.12 ± 0.07 ± 0.02 , S B 0 → J / ψ K S 0 = 0.83 ± 0.08 ± 0.01 , C B 0 → ψ 2 S K S 0 = − 0.05 ± 0.10 ± 0.01 , S B 0 → ψ 2 S K S 0 = 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 $$ {B}^0-{\overline{B}}^0 $$ 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 are $$ \begin{array}{l}C\left({B}^0\to \left[c\overline{c}\right]{K}_{\mathrm{S}}^0\right)=-0.017\pm 0.029,\\ {}S\left({B}^0\to \left[c\overline{c}\right]{K}_{\mathrm{S}}^0\right)=0.760\pm 0.034,\end{array} $$ C B 0 → c c ¯ K S 0 = − 0.017 ± 0.029 , S B 0 → c c ¯ K S 0 = 0.760 ± 0.034 , under the assumption that higher-order contributions to the decay amplitudes are negligible. The uncertainties include statistical and systematic contributions.
Type of Medium:
Online Resource
ISSN:
1029-8479
DOI:
10.1007/JHEP11(2017)170
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2017
detail.hit.zdb_id:
2027350-2
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