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

TL;DR

This paper reports the first observation of the decay $B^{+} o D_s^{+}K^{+}K^{-}$ with a measured branching fraction, and sets an upper limit on the rare decay $B^{+} o D_s^{+}\phi$, using LHCb data.

Contribution

First observation of $B^{+} o D_s^{+}K^{+}K^{-}$ decay and a new upper limit on $B^{+} o D_s^{+}\phi$ decay branching fraction.

Findings

Measured branching fraction of $B^{+} o D_s^{+}K^{+}K^{-}$ as $(7.1 imes 10^{-6})$

No significant signal for $B^{+} o D_s^{+}\phi$, upper limit set

Data collected at 7, 8, and 13 TeV with 4.8 fb$^{-1}$ luminosity

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 13$\,$TeV 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 $B^{+} \to D_s^{+} \overline{\kern -0.2em D}^{0}$. A search is also performed for the pure annihilation decay $B^{+} \to D_s^{+}\phi$. No significant signal is observed and a limit of \begin{equation*} \mathcal{B}(B^{+} \to D_s^{+}\phi) < 4.9 \times 10^{-7}~(4.2 \times 10^{-7}) \end{equation*} is set on the branching fraction at 95$\%$ (90$\%$) confidence level.