Measurement of the branching fractions of the decays $D^{+}\to K^{-}{K}^{+}{K}^{+}$, $D^{+}\to \ddot{I}{€}^{-}\ddot{I}{€}^{+}{K}^{+}$ and $D_s^{+}\to \ddot{I}{€}^{-}{K}^{+}{K}^{+}$

Abstract

The branching fractions of the doubly Cabibbo-suppressed decays $D^{+}\to K^{-}{K}^{+}{K}^{+}$, $D^{+}\to \ddot{I}{€}^{-}\ddot{I}{€}^{+}{K}^{+}$ and $D_s^{+}\to \ddot{I}{€}^{-}{K}^{+}{K}^{+}$ are measured using the decays $D^{+}\to K^{-}\ddot{I}{€}^{+}\ddot{I}{€}^{+}$ and $D_s^{+}\to K^{-}{K}^{+}\ddot{I}{€}^{+}$ as normalisation channels. The measurements are performed using proton-proton collision data collected with the LHCb detector at a centre-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 2.0 fb${}^{-1}$. The results are \begin{align} \frac {\mathcal{B}(D^+\rightarrow K^-K^+K^+)} {\mathcal{B}(D^+\rightarrow K^-π^+π^+)}& = (6.541 \pm 0.025 \pm 0.042) \times 10^{-4},\nonumber \frac {\mathcal{B}(D^+\rightarrow π^-π^+K^+)} {\mathcal{B}(D^+\rightarrow K^-π^+π^+)}& = (5.231 \pm 0.009 \pm 0.023) \times 10^{-3}, \nonumber \frac {\mathcal{B}(D^+_s\rightarrowπ^-K^+K^+)} {\mathcal{B}(D^+_s\rightarrow K^-K^+π^+)}& = (2.372 \pm 0.024 \pm 0.025) \times 10^{-3},\nonumber \end{align} where the uncertainties are statistical and systematic, respectively. These are the most precise measurements up to date.

All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2018-033.html