Measurement of D0-D̄0 mixing and CP violation in two-body D0 decays

Abstract

We present a measurement of D0-D̄0 mixing and CP violation using the ratio of lifetimes simultaneously extracted from a sample of D0 mesons produced through the flavor-tagged process D*+→D0π+, where D0 decays to Kâπ ±, K-K+, or π -π+, along with the untagged decays D0→K âπ± and D0→K-K +. The lifetimes of the CP-even, Cabibbo-suppressed modes K -K+ and π-π+ are compared to that of the CP-mixed mode Kâπ± in order to measure yCP and ΔY. We obtain yCP=[0.72±0. 18(stat)±0.12(syst)]% and ΔY=[0.09±0.26(stat)±0. 06(syst)]%, where ΔY constrains possible CP violation. The yCP result excludes the null mixing hypothesis at 3.3σ significance. This analysis is based on an integrated luminosity of 468 fb-1 collected with the BABAR detector at the PEP-II asymmetric-energy e+e - collider. © 2013 American Physical Society.