Measurement of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>e</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>e</mml:mi><mml:mo>−</mml:mo></mml:msup><mml:mo>→</mml:mo><mml:mi>J</mml:mi><mml:mo>/</mml:mo><mml:mi>ψ</mml:mi><mml:mi>c</mml:mi><mml:mover accent="true"><mml:mi>c</mml:mi><mml:mo>¯</mml:mo></mml:mover></mml:math>cross section at<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt><mml:mo>≈</mml:mo><mml:mn>10.6</mml:mn><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mi>GeV</mml:mi></mml:math>

We present a new measurement of the ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}J/\ensuremath{\psi}c\overline{c}$ cross section where the $c\overline{c}$ pair can fragment either into charmed hadrons or a charmonium state. In the former case the $J/\ensuremath{\psi}$ and a charmed hadron are reconstructed, while the latter process is measured using the recoil mass technique, which allows the identification of two-body final states without reconstruction of one of the charmonia. The measured ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}J/\ensuremath{\psi}c\overline{c}$ cross section is $(0.74\ifmmode\pm\else\textpm\fi{}0.08\genfrac{}{}{0}{}{+0.09}{\ensuremath{-}0.08})\text{ }\text{ }\mathrm{pb}$, and the ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}J/\ensuremath{\psi}{X}_{\mathrm{non}\mathrm{\text{\ensuremath{-}}}c\overline{c}}$ cross section is $(0.43\ifmmode\pm\else\textpm\fi{}0.09\ifmmode\pm\else\textpm\fi{}0.09)\text{ }\text{ }\mathrm{pb}$. We note that the measured cross sections are obtained from a data sample with the multiplicity of charged tracks in the event larger than 4; corrections for the effect of this requirement are not performed as this cannot be done in a model-independent way. The analysis is based on a data sample with an integrated luminosity of $673\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ recorded near the $\ensuremath{\Upsilon}(4S)$ resonance with the Belle detector at the KEKB ${e}^{+}{e}^{\ensuremath{-}}$ asymmetric-energy collider.