Exclusion of multifold solutions of the CKM Unitarity Triangle by a time-dependent Dalitz plot analysis of ${\bar{B}}^0\to D^{(\ast )0}{h}^0$ with $D^0\to K_S^0{\pi }^{+}{\pi }^{-}$ decays combining BABAR and Belle data

We present results of a new analysis campaign, which combines the final data samples collected by the B factory experiments BABAR and Belle in single physics analyses to achieve a unique sensitivity in time-dependent \CP
violation measurements. The data samples contain $(471 \pm 3) \times 10^6 ~B \bar B$pairsrecordedbytheBABARdetectorand$(772 \pm 11) \times 10^6 ~ B \bar B$pairsrecordedbytheBelledetectorin$e^+e^-$ collisions at the center-of-mass energies corresponding to the mass of the $\mathrm{{\rm Y}}(4S)$ resonance at the asymmetric-energy $B$ factories PEP-II at SLAC and KEKB at KEK, respectively. We present a measurement of $\sin 2\beta$ and $\cos 2\beta$ by a time-dependent Dalitz plot analysis of $B^0\to D^{(\ast )}{h}^0$ with $D \to K^0_S \pi^+\pi^-$decays\mathrm{.}Afirstevidencefor$\cos 2\beta >0$, the exclusion of trigonometric multifold solutions of the Unitarity Triangle and an observation of \CP\ violation are reported.