First observation of the $B^+ \rightarrow D_s^+ D_s^- K^+$ decay

TL;DR

This paper reports the first observation of the decay $B^+ ightarrow D_s^+ D_s^- K^+$ using LHCb data, measuring its branching fraction relative to a known decay, and expanding understanding of specific quark transition processes.

Contribution

The paper presents the first experimental observation of the $B^+ ightarrow D_s^+ D_s^- K^+$ decay and measures its branching fraction relative to a similar decay, filling a gap in knowledge of $ar{b} ightarrow ar{c} c ar{s}$ transitions.

Findings

First observation of the decay $B^+ ightarrow D_s^+ D_s^- K^+$.

Measured branching fraction ratio: 0.525 ± 0.033 (stat) ± 0.027 (syst) ± 0.034 (branching fractions).

Fills an experimental gap in Cabibbo-favored $ar{b} ightarrow ar{c} c ar{s}$ transitions.

Abstract

The $B^+ \rightarrow D_s^+ D_s^- K^+$ decay is observed for the first time using proton-proton collision data collected by the LHCb detector at centre-of-mass energies of $7$, $8$ and $13\, \text{TeV}$, corresponding to an integrated luminosity of $9\,\text{fb}^{-1}$. Its branching fraction relative to that of the $B^{+} \rightarrow D^{+} D^{-} K^{+}$ decay is measured to be $$\frac{B\left(B^{+} \rightarrow D_s^{+} D_s^{-} K^{+}\right)}{B\left(B^{+} \rightarrow D^{+} D^{-} K^{+}\right)}=0.525 \pm 0.033 \pm 0.027 \pm 0.034,$$ where the first uncertainty is statistical, the second systematic, and the third is due to the uncertainties on the branching fractions of the $D_s^{\pm} \rightarrow K^{\mp} K^{\pm} \pi^{\pm}$ and $D^{\pm} \rightarrow K^{\mp} \pi^{\pm} \pi^{\pm}$ decays. This measurement fills an experimental gap in the knowledge of the family of Cabibbo$-$favoured $\bar{b} \rightarrow \bar{c} c \bar{s}$ transitions and opens the path for unique studies of spectroscopy in future.