Measurement of the ${\gamma }^{\star }{\gamma }^{\star }\to {\eta }^{\prime }$ transition form factor

Abstract

We study the process $e^{+}{e}^{-}\to e^{+}{e}^{-}{\eta }^{\prime }$ in the double-tag mode and measure for the first time the ${\gamma }^{\star }{\gamma }^{\star }\to {\eta }^{\prime }$ transition form factor $F_{{\eta }^{\prime }}(Q_1^2,Q_2^2)$ in the momentum-transfer range \mbox{2 $<Q_1^2,Q_2^2<$ 60 GeV${}^2$}. The analysis is based on a data sample corresponding to an integrated luminosity of around 469 fb${}^{-1}$ collected at the PEP-II $e^{+}{e}^{-}$ collider with the BaBar detector at center-of-mass energies near 10.6 GeV.

13 pages, 10 figures, submitted to Phys. Rev. D