The $e^{+}{e}^{-}\to J\mathrm{/}\psi D\bar{D}$, $J\mathrm{/}\psi D{\bar{D}}^{\ast }$ reactions with dynamically generated resonances

In two recent reactions by Belle producing $D\bar{D}$ and $D{\bar{D}}^{\ast }$ meson pairs, peaks above threshold have been measured in the differential cross sections, possibly indicating new resonances in these channels. We want to study such reactions from the point of view that the $D$ meson pairs are produced from already known or predicted resonances below threshold. Our study shows that the peak in the $D{\bar{D}}^{\ast }$ production is not likely to be caused by the X(3872) resonance, but the peak seen in $D\bar{D}$ invariant mass can be well described if the $D\bar{D}$ pair comes from the already predicted scalar X(3700) resonance.