First observation of CP violation in the decays of Bs mesons

Abstract : Using pp collision data, corresponding to an integrated luminosity of $1.0 \mathrm{fb}^{-1}$, collected by LHCb in 2011 at a center-of-mass energy of 7 TeV, we report the measurement of direct CP violation in $B^0_s \to K^-\pi^+$ decays, $A_{C/!P}(B^0_s \rightarrow K^- \pi^+)=0.27 \pm 0.04\,\mathrm{(stat)} \pm 0.01\,\mathrm{(syst)}$, with significance exceeding five standard deviations. This is the first observation of CP violation in the decays of $B^0_s$ mesons. Furthermore, we provide an improved determination of direct CP violation in $B^0 \to K^+\pi^-$ decays, $A_{C/!P}(B^0\rightarrow K^+ \pi^-)=-0.080 \pm 0.007\,\mathrm{(stat)} \pm 0.003\,\mathrm{(syst)}$, which is the most precise measurement of this quantity to date.
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Journal articles

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Submitted on : Wednesday, April 24, 2013 - 10:00:45 AM
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Citation

R. Aaij, Y. Amhis, S. Barsuk, O. Callot, J. He, et al.. First observation of CP violation in the decays of Bs mesons. Physical Review Letters, American Physical Society, 2013, 110, pp.221601. ⟨10.1103/PhysRevLett.110.221601⟩. ⟨in2p3-00817212⟩

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