%0 Article %A Lees, J. P. %I American Physical Society %D 2021 %G English %T Measurement of the %U https://hdl.handle.net/1721.1/136942 %X We study the process e^{+}e^{-}→e^{+}e^{-}η^{′} in the double-tag mode and measure for the first time the γ^{⋆}γ^{⋆}→η^{′} transition form factor F_{η^{′}}(Q_{1}^{2},Q_{2}^{2}) in the momentum-transfer range 2