Study of the ${\eta}^{\prime}$ ${\to}$ $Ve^{+}e^{-}$ decay with hidden   local symmetry model
  Within the hidden local symmetry framework, the Dalitz decay ${\eta}^{\prime}$ ${\to}$ $Ve^{+}e^{-}$ is studied with the vector meson dominance model. It is found that the partial width ${\Gamma}({\eta}^{\prime}{\to}{\omega}e^{+}e^{-})$ ${\approx}$ $40$ eV and branching ratio ${\cal B}({\eta}^{\prime}{\to}{\omega}e^{+}e^{-})$ ${\approx}$ $2{\times}10^{-4}$, and ${\Gamma}({\eta}^{\prime}{\to}{\rho}e^{+}e^{-})$ ${\approx}$ $10{\Gamma}({\eta}^{\prime}{\to}{\omega}e^{+}e^{-})$ and ${\cal B}({\eta}^{\prime}{\to}{\rho}e^{+}e^{-})$ ${\approx}$ $10{\cal B}({\eta}^{\prime}{\to}{\omega}e^{+}e^{-})$. The maximum position of the dilepton distribution is $m_{e^{+}e^{-}}$ ${\approx}$ $1.33$ MeV. These decays are measurable with the advent of high statistics ${\eta}^{\prime}$ experiments. 
Yueling Yang, Jinshu Huang, Gongru Lu
hep-ph