### Speaker

### Description

A time-dependent analysis of the $B$ meson decays governed by $b\to c\overline{u}d$

quark transition allows to measure the CKM angle $\varphi_1$ with a negligible effects

of strong interactions. The binned Dalitz plot technique is a promising approach for a

model-independent measurement of the angle $\varphi_1$ in the $B^0\to \overline{D}{}^0\pi^0$

and $B^0\to \overline{D}{}^0\pi^+\pi^-$ decays followed by $\overline{D}{}^0$ decays into

$K_S^0\pi^+\pi^-$ and CP-eigenstates. We apply this technique to a full data sample of

the Belle experiment and perform a time-dependent analysis of $B^0 \to \overline{D}{}^{(*)0}h^0$,

$\overline{D}{}^0\to K_S^0\pi^+\pi^-$ decays, where $h^0\in\{\pi^0, \eta^{(\prime)}, \omega\}$.

The obtained value $\cos{2\varphi_1} = 1.06\pm0.33{}^{+0.21}_{-0.15}$ is the most precise

single measurement of the $\cos{2\varphi_1}$ to date and resolves the twofold ambiguity at

the confidence level exceeding five standard deviations. The binned Dalitz plot technique can

be employed to measure the angle $\varphi_1$ in the $b\to c\overline{u}d$ transitions at

the precision level of one degree with expected statistics of the LHCb and Belle II experiments.

Such precise results together with measurements of the $b\to c\overline{c}s$ transition

would provide a valuable check of the KM mechanism.