Study of $CP$ violation in $B_{(s)}^0\to D{K}^{\ast }(892{)}^0$ decays with $D\to K\pi (\pi \pi )$, $\pi \pi (\pi \pi )$, and $KK$ final states

A measurement of $CP$-violating observables associated with the interference of $B^0\to D^0{K}^{\ast }(892{)}^0$ and $B^0\to {\bar{D}}^0{K}^{\ast }(892{)}^0$ decay amplitudes is performed in the $D^0\to K^{\mp }{\pi }^{\pm }({\pi }^{+}{\pi }^{-}),$ $D^0\to {\pi }^{+}{\pi }^{-}({\pi }^{+}{\pi }^{-})$, and $D^0\to K^{+}{K}^{-}$ final states using data collected by the LHCb experiment corresponding to an integrated luminosity of $9$ ${\text{fb}}^{-1}$. $CP$-violating observables related to the interference of $B_s^0\to D^0{\bar{K}}^{\ast }(892{)}^0$ and $B_s^0\to {\bar{D}}^0{\bar{K}}^{\ast }(892{)}^0$ are also measured, but no evidence for interference is found. The $B^0$ observables are used to constrain the parameter space of the CKM angle $\gamma$ and the hadronic parameters $r_{B^0}^{D{K}^{\ast }}$ and ${\delta }_{B^0}^{D{K}^{\ast }}$ with inputs from other measurements. In a combined analysis, these measurements allow for four solutions in the parameter space, only one of which is consistent with the world average.