Evidence for Direct CP Violation in the Measurement of the Cabbibo-Kobayashi-Maskawa Angle γ with B∓→D(*)K(*)∓ Decays

Abstract

We report the measurement of the Cabibbo-Kobayashi-Maskawa C P -violating angle γ through a Dalitz plot analysis of neutral D -meson decays to K 0 S π + π − and K 0 S K + K − produced in the processes B ∓ → D K ∓ , B ∓ → D ∗ K ∓ with D ∗ → D π 0 , D γ , and B ∓ → D K * ∓ with K * ∓ → K 0 S π ∓ , using 468 million B ¯¯¯ B pairs collected by the BABAR detector at the PEP-II asymmetric-energy e + e − collider at SLAC. We measure γ = ( 68 ± 14 ± 4 ± 3 ) ° (modulo 180°), where the first error is statistical, the second is the experimental systematic uncertainty, and the third reflects the uncertainty in the description of the neutral D decay amplitudes. This result is inconsistent with γ = 0 (no direct C P violation) with a significance of 3.5 standard deviations.