Observation of direct CP violation in the measurement of the Cabibbo-Kobayashi-Maskawa angle γ with B±→D(*)K(*)± decays

Abstract

We report the determination of the Cabibbo-Kobayashi-Maskawa C P -violating angle γ through the combination of various measurements involving B ± → D K ± , B ± → D ∗ K ± , and B ± → D K * ± decays performed by the BABAR experiment at the PEP-II e + e − collider at SLAC National Accelerator Laboratory. Using up to 474 million B ¯¯¯ B pairs, we obtain γ = ( 69 + 17 − 16 ) ° modulo 180°. The total uncertainty is dominated by the statistical component, with the experimental and amplitude-model systematic uncertainties amounting to ± 4 ° . The corresponding two-standard-deviation region is 41 ° < γ < 102 ° . This result is inconsistent with γ = 0 with a significance of 5.9 standard deviations.