LHCb: Measurements of the relative branching fractions of the decay channel $B^{\pm}\to p \bar{p} K^{\pm}$ including charmonium contributions at LHCb

The study of the $B^{\pm}\to p \bar{p} K^{\pm}$ decay channel at LHCb is of great interest since it gives the possibility to study different aspects of the Standard Model and possibly Beyond Standard Model physics. A measurement of the direct CP asymmetry can be performed. Moreover intermediate states such as charmonium and "charmonium-like" resonances in the $p \bar{p}$ final state can be observed and studied along with their characteristics. A multivariate selection has been implemented to select the interesting events using kinematic and topological variables and the particle identification information using the Ring Imaging Cherenkov detectors. The selection has a high signal efficiency and high background rejection capability. The ratios of the branching fractions of the $B^{\pm}\to p \bar{p} K^{\pm}$ decay channel, of the charmless component with $M_{p \bar{p}} < 2.85 \,{\rm GeV/}c^{2}$ and of the charmonium contribution $\eta_{c}$, ${\mathcal B} (B^{\pm}\to \eta_{c} K^{\pm})\times {\mathcal B} (\eta_{c} \to p \bar {p})$, relative to the $J/\psi$ contribution, ${\mathcal B} (B^{\pm}\to J/\psi K^{\pm})\times {\mathcal B} (J/\psi \to p \bar{p})$, have been measured and the results will be shown.