Measurement ofJ/ψProduction in Continuume+e−Annihilations near√s=10.6GeV

The production of $J/\ensuremath{\psi}$ mesons in continuum ${e}^{+}{e}^{\ensuremath{-}}$ annihilations has been studied with the BABAR detector at energies near the $\ensuremath{\Upsilon}(4S)$ resonance. The mesons are distinguished from $J/\ensuremath{\psi}$ production in $B$ decays through their center-of-mass momentum and energy. We measure the cross section ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}J/\ensuremath{\psi}X$ to be $2.52\ifmmode\pm\else\textpm\fi{}0.21\ifmmode\pm\else\textpm\fi{}0.21\mathrm{pb}$. We set a $90%$ C.L. upper limit on the branching fraction for direct $\ensuremath{\Upsilon}(4S)\ensuremath{\rightarrow}J/\ensuremath{\psi}X$ decays at $4.7\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$.