Dalitz analysis of neutral D meson decays to neutral kaon(short) pion(+) pion(-) and measurement of the CKM angle gamma in charged B meson decays to D meson(*) charged kaon decays

Abstract

We present a measurement of the Cabibbo-Kobayashi-Maskawa CP -violating phase γ with a Dalitz analysis of neutral D-meson decays to the [special characters omitted]π⁺π^- final state occurring in B^± → D^(∗) K^± decays. The data sample consists of 347 million e⁺e ^- → ϒ(4S) → BB events collected by the BABAR detector at the Stanford Linear Accelerator Center's PEP-II asymmetric-energy e⁺ e^- collider. We measure γ = (92±41±11±12)°, where the first error is statistical, the second is the experimental systematic uncertainty, and the third reflects the Dalitz model uncertainty. For the ratios [special characters omitted] of the magnitudes of the amplitudes [special characters omitted](B^- → D ^(∗)0K^-) and [special characters omitted](B^- → D ^-(∗)0K^-) we obtain the one standard deviation intervals [0; 0.14] and [0.02; 0.20], respectively. We also present a study of the Dalitz plot in the decay D ⁰ → [special characters omitted]π⁺π^- using approximately 250000 events collected by the BABAR detector. We characterize the S-wave (spin-0) component of the π⁺π^- system using the K-matrix formalism, which is needed to describe the broad overlapping resonance structure in this decay. The results are compared and discussed with the traditional two-body (isobar) model, which is used in the determination of the CKM angle γ from charged B decays.