# Observation of ${B}_{s}^{0}\to {\overline{D}}^{*0}\varphi$ and search for ${B}^{0}\to {\overline{D}}^{0}\varphi$ decays

30 October 2018

Abstract: The first observation of the ${B}_{s}^{0}\to {\overline{D}}^{*0}\varphi$ decay is reported, with a significance of more than seven standard deviations, from an analysis of $pp$ collision data corresponding to an integrated luminosity of $3\text{}\text{}{\mathrm{fb}}^{-1}$, collected with the LHCb detector at center-of-mass energies of 7 and 8 TeV. The branching fraction is measured relative to that of the topologically similar decay ${B}^{0}\to {\overline{D}}^{0}{\pi }^{+}{\pi }^{-}$ and is found to be $B\left({B}_{s}^{0}\to {\overline{D}}^{*0}\varphi \right)=\left(3.7±0.5±0.3±0.2\right)×1{0}^{-5}$, where the first uncertainty is statistical, the second systematic, and the third from the branching fraction of the ${B}^{0}\to {\overline{D}}^{0}{\pi }^{+}{\pi }^{-}$ decay. The fraction of longitudinal polarization in this decay is measured to be ${f}_{L}=\left(73±15±4\right)%$. The most precise determination of the branching fraction for the ${B}_{s}^{0}\to {\overline{D}}^{0}\varphi$ decay is also obtained, $B\left({B}_{s}^{0}\to {\overline{D}}^{0}\varphi \right)=\phantom{\rule{0ex}{0ex}}\left(3.0±0.3±0.2±0.2\right)×1{0}^{-5}$. An upper limit, $B\left({B}^{0}\to {\overline{D}}^{0}\varphi \right)<2.0$ $\left(2.3\right)×1{0}^{-6}$ at 90% (95%) confidence level is set. A constraint on the $\omega -\varphi$ mixing angle $\delta$ is set at $|\delta |<5.2°$ (5.5°) at 90% (95%) confidence level.

Published in: Physical Review D 98 (2018)