We report on the measurement of the beam asymmetry $\mathrm{\Sigma }$ for the reactions $\vec{\gamma }p\to p\eta$ and $\vec{\gamma }p\to p{\eta }^{\prime }$ from the GlueX experiment using an 8.2–8.8-GeV linearly polarized tagged photon beam incident on a liquid hydrogen target in Hall D at Jefferson Laboratory. These measurements are made as a function of momentum transfer $-t$ with significantly higher statistical precision than our earlier $\eta$ measurements and are the first measurements of ${\eta }^{\prime }$ in this energy range. We compare the results to theoretical predictions based on $t$-channel quasiparticle exchange. We also compare the ratio of ${\mathrm{\Sigma }}_{\eta }$ to ${\mathrm{\Sigma }}_{{\eta }^{\prime }}$ to these models as this ratio is predicted to be sensitive to the amount of $s\overline{s}$ exchange in the production. We find that photoproduction of both $\eta$ and ${\eta }^{\prime }$ is dominated by natural parity exchange with little dependence on $-t$.

• Received 16 August 2019

DOI:https://doi.org/10.1103/PhysRevC.100.052201