Measurement of CP violation in B0 → J/ψKS0 and B0 → ψ(2S)KS0 decays
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Author(s)
Aaij, R.
Adeva, B.
Adinolfi, M.
Ajaltouni, Z.
Akar, S.
Albrecht, J.
Alessio, F.
Alexander, M.
Alfonso Albero, A.
Ali, S.
Date Issued
November 2017
Journal
Journal of High Energy Physics
Publisher
Springer Berlin Heidelberg
Citation
Aaij, R. et al. "Measurement of CP violation in B⁰ → J/ψK[subscript S]⁰ and B⁰ → ψ(2S)K[subscript S]0 decays." Journal of High Energy Physics 2017 (November 2017): 170 © 2017 The Author(s)
Version
Final published version
Abstract
Abstract
A measurement is presented of decay-time-dependent CP violation in the decays B0 → J/ψ K
S
0
and B0 → 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 be
A measurement is presented of decay-time-dependent CP violation in the decays B⁰ → J/ψK[subscript S]⁰ and B⁰ → ψ(2S)K[subscript 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 be C(B⁰ → J/ψ K[subscript S]⁰) = 0.12 ± 0.07 ± 0.02, S(B⁰ → J/ψ K[subscript S]⁰) = 0.83 ± 0.08 ± 0.01, C(B⁰ → ψ(2S)[subscript S]⁰) = −0.05 ± 0.10 ± 0.01, S(B⁰ → ψ(2S)K[subscript 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 B⁰−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 B0 → J/ψ K S0 decays, where the J/ψ meson was reconstructed from two muons. The averages of all three sets of LHCb results are C(B⁰ → (cc ¯)K[subscript S]⁰) = − 0.017 ± 0.029, S(B⁰ → (cc ¯) K[subscript 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.
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
,
$$ \begin{array}{l}C\left({B}^0\to J/\psi \kern0.5em {K}_{\mathrm{S}}^0\right)=0.12\pm 0.07\pm 0.02,\\ {}S\left({B}^0\to J/\psi \kern0.5em {K}_{\mathrm{S}}^0\right)=0.83\pm 0.08\pm 0.01,\\ {}C\left({B}^0\to \psi (2S){K}_{\mathrm{S}}^0\right)=-0.05\pm 0.10\pm 0.01,\\ {}S\left({B}^0\to \psi (2S){K}_{\mathrm{S}}^0\right)=0.84\pm 0.10\pm 0.01,\end{array} $$
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
$$ {B}^0-{\overline{B}}^0 $$
oscillation. The first uncertainties are statistical and the second are systematic. The two sets of results are compatible with the previous LHCb measurement using B0 → 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
C
B
0
→
c
c
¯
K
S
0
=
−
0.017
±
0.029
,
S
B
0
→
c
c
¯
K
S
0
=
0.760
±
0.034
,
$$ \begin{array}{l}C\left({B}^0\to \left[c\overline{c}\right]{K}_{\mathrm{S}}^0\right)=-0.017\pm 0.029,\\ {}S\left({B}^0\to \left[c\overline{c}\right]{K}_{\mathrm{S}}^0\right)=0.760\pm 0.034,\end{array} $$
under the assumption that higher-order contributions to the decay amplitudes are negligible. The uncertainties include statistical and systematic contributions.
MIT Department
Massachusetts Institute of Technology. Department of Physics
Massachusetts Institute of Technology. Laboratory for Nuclear Science
Terms of Use
Creative Commons Attribution
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1007/JHEP11(2017)170
