Measurement of the space-like $\ddot{I}{€}^0$ transition form factor

Abstract

Based on $2.93{\text{fb}}^{-1}$ of $e^{+}{e}^{-}$ collision data taken with the BESIII detector at a center-of-mass energy of $3.773\text{GeV}$, the two-photon fusion process $e^{+}{e}^{-}\to e^{+}{e}^{-}\ddot{I}{€}^0$ is investigated using a single-tag approach. The differential Born cross section $\text{d}\ddot{I}ƒ/\text{d}{Q}^2$ and the space-like transition form factor $|F(Q^2)|$ of the $\ddot{I}{€}^0$ are measured as functions of the squared momentum transfer $Q^2$ of the tagged, scattered lepton. The measurement covers the range $0.2<Q^2<3.5{\text{GeV}}^2$. The results are consistent with previous measurements, and provide a significant improvement for $Q^2<2{\text{GeV}}^2$.

14 pages, 3 figures, submitted to Phys.Lett.B