Evidence for CP Violation in B+ -> p(p)over-barK(+) Decays

Three-body B+\u2192pp\uafK+ and B+\u2192pp\uaf\u3c0+ decays are studied using a data sample corresponding to an integrated luminosity of 3.0fb-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+\u2192pp\uafK+ 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 pp\uaf rest frame yield AFB(pp\uafK+,mpp\uaf<2.85GeV/c2)=0.495\ub10.012(stat)\ub10.007(syst) and AFB(pp\uaf\u3c0+,mpp\uaf<2.85GeV/c2)=-0.409\ub10.033(stat)\ub10.006(syst). In addition, the branching fraction of the decay B+\u2192\u39b\uaf(1520)p is measured to be B(B+\u2192\u39b\uaf(1520)p)=(3.15\ub10.48(stat)\ub10.07(syst)\ub10.26(BF)) 710-7, where BF denotes the uncertainty on secondary branching fractions