Evidence for CP violation in $B^{+}\to p\bar{p}{K}^{+}$ decays

Abstract

Three-body $B^{+}\to p\overline{p}{K}^{+}$ and $B^{+}\to p\overline{p}\ddot{I}{€}^{+}$ decays are studied using a data sample corresponding to an integrated luminosity of 3.0 $f{b}^{-1}$ 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 $A_{\mathrm{FB}}(p\overline{p}{K}^{+},m_{p\overline{p}}<2.85\mathrm{Ge}\mathrm{V}/c^2)=0.495\pm 0.012(\mathrm{stat})\pm 0.007(\mathrm{syst})$ and $A_{\mathrm{FB}}(p\overline{p}\ddot{I}{€}^{+},m_{p\overline{p}}<2.85\mathrm{Ge}\mathrm{V}/c^2)=-0.409\pm 0.033(\mathrm{stat})\pm 0.006(\mathrm{syst})$. In addition, the branching fraction of the decay $B^{+}\to \overline{\hat{I}›}(1520)p$ is measured to be $\mathcal{B}(B^{+}\to \overline{\hat{I}›}(1520)p)=(3.15\pm 0.48(\mathrm{stat})\pm 0.07(\mathrm{syst})\pm 0.26(\mathrm{BF}))\times 10^{-7}$, where BF denotes the uncertainty on secondary branching fractions.

17 pages, 8 figures