Measurements of the Absolute Branching Fractions of $B^{\pm }\to K^{\pm }{X}_{c\bar{c}}$

Abstract

A study of the two body decays $B^{\pm }\to X_{c\bar{c}}{K}^{\pm }$, where X${}_{c\bar{c}}$ refers to one charmonium state, is reported by BaBar collaboration using a data sample of 424 fb${}^{-1}$. The absolute determination of branching fractions for these decays are significantly improved compared to previous BaBaR measurements. Evidence is found for the decay $B^{+}\to X(3872)K^{+}$ at the $3\ddot{I}ƒ$ level. The absolute branching fraction $\mathcal{B}(B^{+}\to X(3872)K^{+})=(2.1\pm 0.6(\mathrm{stat})\pm 0.3(\mathrm{syst}))\times 10^{-4}$ is measured for the first time. It follows that $\mathcal{B}(X(3872)\to J/\ddot{I}ˆ\ddot{I}{€}^{+}\ddot{I}{€}^{-})=(4.1\pm 1.3)\%$, supporting the hypothesis of a molecular component for this resonance.

8 pages 6 figures