Improved measurement of the CKM angle γ in B∓→D(*)K(*)∓ decays with a Dalitz plot analysis of D decays to K0Sπ+π− and K0SK+K−

Abstract

We report on an improved measurement of the Cabibbo-Kobayashi-Maskawa C P -violating phase 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 a sample of 383 × 10 6 B ¯¯¯ B pairs collected by the BABAR detector, we measure γ = ( 76 ± 22 ± 5 ± 5 ) ° (mod 180°), where the first error is statistical, the second is the experimental systematic uncertainty, and the third reflects the uncertainty on the description of the Dalitz plot distributions. The corresponding 2-standard-deviation region is 29 ° < γ < 122 ° . This result has a significance of direct C P violation ( γ ≠ 0 ) of 3.0 standard deviations.