Measurement of the CKM angle γ using B^± → DK^± with D → K⁰_sπ⁺π⁻, K⁰_sK⁺K⁻ decays

A binned Dalitz plot analysis of B^± → DK^± decays, with D → K⁰_Sπ⁺π⁻ and D → K⁰_SK⁺K⁻, is performed to measure the CP -violating observables x_± and y_±, which are sensitive to the Cabibbo-Kobayashi-Maskawa angle γ. The analysis exploits a sample of proton-proton collision data corresponding to 3.0 fb⁻¹ collected by the LHCb experiment. Measurements from CLEO-c of the variation of the strong-interaction phase of the D decay over the Dalitz plot are used as inputs. The values of the parameters are found to be x₊ = (−7.7±2.4±1.0±0.4) × 10⁻², x₋ = (2.5±2.5±1.0±0.5) × 10⁻², y₊ = (−2.2±2.5±0.4±1.0) × 10⁻², and y₋ = (7.5±2.9± 0.5±1.4) × 10⁻². The first, second, and third uncertainties are the statistical, the experimental systematic, and that associated with the precision of the strong-phase parameters. These are the most precise measurements of these observables and correspond to γ = (62⁺¹⁵₋₁₄)^◦, with a second solution at γ → γ + 180^◦, and r_B = 0.080^+0.019_−0.021, where r_B is the ratio between the suppressed and favoured B decay amplitudes.