Measurement of CP Violation in the Phase Space of B± → K±π+π- and B± → K±K+K- Decays

The charmless decays B-+/- -> K-+/-pi(+)pi(-) and B-+/- -> (KK+K-)-K-+/- are reconstructed using data, corresponding to an integrated luminosity of 1.0 fb(-1), collected by LHCb in 2011. The inclusive charge asymmetries of these modes are measured as A(CP)(B-+/- -> (KK+K-)-K-+/-) =0.032 +/- 0.008(stat)+/- 0.004(syst)+/- 0.007(J/psi K-+/-), and A(CP)(B-+/- -> (KK+K-)-K-+/-) = -0.043 +/- 0.009(stat)+/- 0.003 (syst) = 0.007(J/psi K-+/-), where the third uncertainty is due to the CP asymmetry of the B-+/- -> J/psi K-+/- reference mode. The significance of A(CP)(B-+/- -> (KK+K-)-K-+/-) exceeds three standard deviations and is the first evidence of an inclusive CP asymmetry in charmless three- body B decays. In addition to the inclusive CP asymmetries, larger asymmetries are observed in localized regions of phase space.