# Evidence for CP violation in $B^+\to p \overline p K^+$ decays

Abstract : Three-body $B^+\to p \overline p K^+$ and $B^+\to p \overline p \pi^+$ decays are studied using a data sample corresponding to an integrated luminosity of 3.0 $fb^{-1}$ collected by the LHCb experiment in proton-proton collisions at center-of-mass energies of $7$ and $8$ TeV. Evidence of CP violation in the $B^+\to p \overline p K^+$ decay is found in regions of the phase space, representing the first measurement of this kind for a final state containing baryons. Measurements of the forward-backward asymmetry of the light meson in the $p\overline p$ rest frame yield $A_{\mathrm{FB}}(p \overline p K^+,~m_{p\overline p}<2.85\mathrm{\,Ge\kern -0.1em V\!/}c^2)=0.495\pm0.012~(\mathrm{stat})\pm0.007~(\mathrm{syst})$ and $A_{\mathrm{FB}}(p\overline p \pi^+,~m_{p\overline p}<2.85\mathrm{\,Ge\kern -0.1em V\!/}c^2)=-0.409\pm0.033~(\mathrm{stat})\pm0.006~(\mathrm{syst})$. In addition, the branching fraction of the decay $B^+\to\kern 0.1em\overline{\kern -0.1em\Lambda}(1520)p$ is measured to be $\mathcal{B}(B^+ \to \kern 0.1em\overline{\kern -0.1em\Lambda}(1520)p)=(3.15\pm0.48~(\mathrm{stat})\pm0.07~(\mathrm{syst})\pm0.26~(\mathrm{BF}))\times 10^{-7}$, where BF denotes the uncertainty on secondary branching fractions.
Document type :
Journal articles

http://hal.in2p3.fr/in2p3-01038106
Contributor : Sabine Starita <>
Submitted on : Wednesday, July 23, 2014 - 11:52:04 AM
Last modification on : Tuesday, April 20, 2021 - 12:00:14 PM

### Citation

R. Aaij, Y. Amhis, S. Barsuk, M. Borsato, O. Callot, et al.. Evidence for CP violation in $B^+\to p \overline p K^+$ decays. Physical Review Letters, American Physical Society, 2014, 113, pp.141801. ⟨10.1103/PhysRevLett.113.141801⟩. ⟨in2p3-01038106⟩

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