${\psi }^{\prime \prime }\mathrm{}\left(3770\right)\mathrm{}$ resonance and $D\overline{D}$ production above charm threshold in $e^{+}{e}^{-}$ annihilation

On the basis of a field-theoretic quark model proposed recently, the width of ${\psi }^{\prime \prime }\mathrm{}\left(3770\right)\mathrm{}$ has been calculated in terms of quark-model parameters. This has been utilized to obtain $\sigma (e^{+}{e}^{-}\to D\overline{D})$ around the center-of-mass energy corresponding to the ${\psi }^{\prime \prime }$ resonance, where also the effect of $\psi$ and ${\psi }^{\prime }$ as intermediate states for $D\overline{D}$ production has been included. With ${\Gamma }_{\mathrm{ee}}\left({\psi }^{\prime \prime }\right)$ as a free parameter, the results of the calculations have been compared with the experimental results. ${\Gamma }_{\mathrm{ee}}$ appears to be smaller than earlier estimates.