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

The charmless decays B ± → K ± π + π − and B ± → K ± 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 C P ( B ± → K ± π + π − ) = 0.032 ± 0.008 ( stat ) ± 0.004 ( syst ) ± 0.007 ( J / ψ K ± ) and A C P ( B ± → K ± K + K − ) = − 0.043 ± 0.009 ( stat ) ± 0.003 ( syst ) ± 0.007 ( J / ψ K ± ) , where the third uncertainty is due to the C P asymmetry of the B ± → J / ψ K ± reference mode. The significance of A C P ( B ± → K ± K + K − ) exceeds three standard deviations and is the first evidence of an inclusive C P asymmetry in charmless three-body B decays. In addition to the inclusive C P asymmetries, larger asymmetries are observed in localized regions of phase space