Measurement of the average φ multiplicity in B meson decay

We present a measurement of the average multiplicity of φ mesons in $B^0,$ $B^0,$ and $B^{\pm }$ meson decays. Using 17.6 ${\mathrm{fb}}^{\mathrm{-}1}$ of data taken at the ${\rm Y}\mathrm{}\left(4S\right)\mathrm{}$ resonance by the BABAR detector at the PEP-II $e^{+}{e}^{-}$ storage ring at the Stanford Linear Accelerator Center, we reconstruct φ mesons in the $K^{+}{K}^{-}$ decay mode and measure $\mathcal{B}\left(\overrightarrow{B}\phi X\right)=(3.41\mathrm{}\pm 0.06\pm 0.12)\%.$ This is significantly more precise than any previous measurement.