Measurement of the Born cross section for at GeV

Using $\textit{e}$ $\textit{e}$ collision data corresponding to a total integrated luminosity of 20 fb collected with the BESIII detector at the BEPCII collider, we present a measurement of the Born cross section for the process at 39 center-of-mass energies between 3.5 and 4.9 GeV with a partial reconstruction technique. By performing a fit to the dressed cross section of with a power law function for continuum production and one resonance at a time for the $\textit{ψ}$(3770), $\textit{ψ}$(4040), $\textit{ψ}$(4160), $\textit{ψ}$(4230), $\textit{ψ}$(4360), $\textit{ψ}$(4415) or $\textit{ψ}$(4660), respectively, the upper limits for the product of partial electronic width and branching fraction into the final state for these resonances are determined at the 90% confidence level.