Beam asymmetry Σ for the photoproduction of η and η' mesons at Eγ=8.8 GeV

We report on the measurement of the beam asymmetry Sigma for the reactions (gamma) over right arrowp -> p eta and (gamma) over right arrowp -> p eta' 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. measurements and are the first measurements of eta' in this energy range. We compare the results to theoretical predictions based on t-channel quasiparticle exchange. We also compare the ratio of Sigma(eta) to Sigma(eta)' to these models as this ratio is predicted to be sensitive to the amount of s (s) over bar exchange in the production. We find that photoproduction of both eta and eta' is dominated by natural parity exchange with little dependence on -t.