Constraints on the unitarity triangle angle $\gamma$ from Dalitz plot analysis of $B^0\to D{K}^{+}{\pi }^{-}$ decays

The first study is presented of CP violation with an amplitude analysis of the Dalitz plot of $B^0\to D{K}^{+}{\pi }^{-}$ decays, with $D\to K^{+}{\pi }^{-}$, $K^+ K^-$and$\pi^+ \pi^-$\mathrm{.}Theanalysisisbasedonadatasamplecorrespondingto$3.0,{\rm fb}^{-1}$of$pp$ collisions collected with the LHCb detector. No significant CP violation effect is seen, and constraints are placed on the angle $\gamma$ of the unitarity triangle formed from elements of the Cabibbo-Kobayashi-Maskawa quark mixing matrix. Hadronic parameters associated with the $B^0\to D{K}^{\ast }(892{)}^0$ decay are determined for the first time. These measurements can be used to improve the sensitivity to $\gamma$ of existing and future studies of the $B^0\to D{K}^{\ast }(892{)}^0$ decay.