Backward-angle electroproduction of $\hat{I}{\cdot }^{\prime }$ mesons off protons at $W=2.13\text{GeV}$ and $Q^2=0.46{\left(\text{GeV}/c\right)}^2$

Abstract

The electroproduction of $\hat{I}{\cdot }^{\prime }$ mesons from a ${}^1\mathrm{H}$ target at $W=2.13\text{GeV}$, $Q^2=0.46{\left(\text{GeV}/c\right)}^2$ and $\cos θ^{\text{CM}}_{γ^{*}η'} \approx -1$ has been experimentally measured. The differential cross section of virtual-photoproduction has been obtained as $4.4\pm 0.8\left(\text{stat.}\right)\pm 0.4\left(\text{sys.}\right)\text{nb/sr}$ in the One-Photon-Exchange Approximation. This value is one-sixth of that of real-photoproduction at backward angles. A comparison with newly-developed isobar model calculations not only shows validity of the theoretical framewark employed, but also imposes new constrains on coupling strength between the $\hat{I}{\cdot }^{\prime }p$ final state and nucleon resonances.

27 pages, 9 figures