Measurement of the branching fraction and $CP$ asymmetry for $B\to {\bar{D}}^0\ddot{I}€$ decays

Abstract

We measure the branching fractions and $CP$ asymmetries for the decays $B^0\to {\bar{D}}^0\ddot{I}{€}^0$ and $B^{+}\to {\bar{D}}^0\ddot{I}{€}^{+}$, using a data sample of $772\times 10^6$ $B\bar{B}$ pairs collected at the $\hat{I}\yen (4S)$ resonance with the Belle detector at the KEKB $e^{+}{e}^{-}$ collider. The branching fractions obtained and direct $CP$ asymmetries are $\mathcal{B}(B^0\to {\bar{D}}^0\ddot{I}{€}^0)=[2.70\pm 0.06\text{(stat.)}\pm 0.10\text{(syst.)}]\times 10^{-4}$, $\mathcal{B}(B^{+}\to {\bar{D}}^0\ddot{I}{€}^{+})=[4.53\pm 0.02\text{(stat.)}\pm 0.15\text{(syst.)}]\times 10^{-3}$, ${\mathcal{A}}_{CP}(B^0\to {\bar{D}}^0\ddot{I}{€}^0)=[+0.42\pm 2.05\text{(stat.)}\pm 1.22\text{(syst.)}]\%$, and ${\mathcal{A}}_{CP}(B^{+}\to {\bar{D}}^0\ddot{I}{€}^{+})=[+0.19\pm 0.36\text{(stat.)}\pm 0.57\text{(syst.)}]\%$. The measurements of $\mathcal{B}$ are the most precise to date and are in good agreement with previous results, as is the measurement of ${\mathcal{A}}_{CP}(B^{+}\to {\bar{D}}^0\ddot{I}{€}^{+})$. The measurement of ${\mathcal{A}}_{CP}$ for $B^0\to {\bar{D}}^0\ddot{I}{€}^0$ is the first for this mode, and the value is consistent with Standard Model expectations.

13 pages, 4 captioned figures, plus supplemental material. Accepted by Phys. Rev. D. Updated for typos and clarity based on journal review