Measurement of γ using B± → DK± and B± → Dπ± decays with $ D\to {K}_{\mathrm{S}}^0{\pi}^{+}{\pi}^{-} $ and $ D\to {K}_{\mathrm{S}}^0{K}^{+}{K}^{-} $

A measurement of the CKM angle γ using the decay channels B ± → DK ± and B ± → Dπ ± , where the D meson decays to $D\to {K}_{\mathrm{S}}^0{\pi}^{+}{\pi}^{-}$ or $D\to {K}_{\mathrm{S}}^0{K}^{+}{K}^{-}$ , is performed with a data sample corresponding to an integrated luminosity of 5.8 fb − 1 , collected during 2024 by the upgraded LHCb experiment. CP violation is observed through a difference in the distributions of the Dalitz plot of the D decay between the B + and B − mesons. The CKM angle γ is determined to be γ = (68 . 1 ± 6 . 7) ° . Other parameters related to the examined B meson decay modes are also measured. This is the first measurement of the CKM angle γ using the upgraded LHCb detector.