First observation of $B^{+}\to D_s^{+}{K}^{+}{K}^{-}$ decays and a search for $B^{+}\to D_s^{+}\ddot{I}•$ decays

Abstract

A search for $B^{+}\to D_s^{+}{K}^{+}{K}^{-}$ decays is performed using $pp$ collision data corresponding to an integrated luminosity of 4.8 fb${}^{-1}$, collected at centre-of-mass energies of 7, 8 and 13TeV with the LHCb experiment. A significant signal is observed for the first time and the branching fraction is determined to be \begin{equation*} \mathcal{B}(B^{+} \to D_s^{+}K^{+}K^{-} ) = (7.1 \pm 0.5 \pm 0.6 \pm 0.7) \times 10^{-6}, \end{equation*} where the first uncertainty is statistical, the second systematic and the third due to the uncertainty on the branching fraction of the normalisation mode $B^{+}\to D_s^{+}{\overline{D}}^0$. A search is also performed for the pure annihilation decay $B^{+}\to D_s^{+}\ddot{I}•$. No significant signal is observed and a limit of \begin{equation*} \mathcal{B}(B^{+} \to D_s^{+}ϕ) < 4.9 \times 10^{-7}~(4.2 \times 10^{-7}) \end{equation*} is set on the branching fraction at 95$\%$ (90$\%$) confidence level.

All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2017-032.html