Speaker
Description
Knowledge on the angles of the Unitarity Triangle provides stringent tests on the Standard Model of electroweak interactions and enables one to constrain potential effects of the physics beyond. The parameter $\sin (2\beta) = \sin (2\phi_1)$ has been precisely measured by the B factory experiments BaBar and Belle using $b \to c \bar{c} s$ transitions such as the golden mode $B^0 \to J/\psi K_S^0$. In terms of the angle $\beta = \phi_1$, the value smaller than $\pi/2$ is favored between two possible solutions, however the discrimination is not evident yet at current experimental status. By reconstructing the neutral $D$ meson decays in self-conjugated multi-body final states, a time-dependent Dalitz analysis in $B^0 \to D^{(*)} h^0$ decays provide a theoretically clean probe to constrain $\cos(2\beta) = \cos(2\phi_1)$. We present a time-dependent Dalitz analysis of $B^0 \to D^{(*)} h^0$ decays followed by the $D$ meson decays to $K_S^0 \pi^+ \pi^-$ where the $h^0$ is a $\pi i^0$, $\eta$ or $\omega$ meson. The measurement is performed by combining the final data samples of $471 \times 10^6$ $B\overline{B}$ pairs and $772 \times 10^6$ $B\overline{B}$ pairs recorded by the BaBar and the Belle experiments, respectively.
