Type: Article
Publication Date: 2021-04-23
Citations: 4
DOI: https://doi.org/10.1103/physrevd.103.076017
Methods for extracting the $\ensuremath{\psi}(3770)\ensuremath{\rightarrow}{e}^{+}{e}^{\ensuremath{-}}$ decay width from the data on the reaction cross section ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}D\overline{D}$ are discussed. Attention is drawn to the absence of the generally accepted method for determining ${\mathrm{\ensuremath{\Gamma}}}_{\ensuremath{\psi}(3770){e}^{+}{e}^{\ensuremath{-}}}$ in the presence of interference between the contributions of the $\ensuremath{\psi}(3770)$ resonance and background. It is shown that the model for the experimentally measured $D$ meson form factor, which satisfies the requirement of the Watson theorem and takes into account the contribution of the complex of the mixed $\ensuremath{\psi}(3770)$ and $\ensuremath{\psi}(2S)$ resonances, allows us to uniquely determine the value of ${\mathrm{\ensuremath{\Gamma}}}_{\ensuremath{\psi}(3770){e}^{+}{e}^{\ensuremath{-}}}$ by fitting. The ${\mathrm{\ensuremath{\Gamma}}}_{\ensuremath{\psi}(3770){e}^{+}{e}^{\ensuremath{-}}}$ values found from the data processing are compared with the estimates in the potential models.