Measurement of the beam asymmetry Σ for π^0 and η photoproduction on the proton at E sub γ=9 GeV

Abstract

We report measurements of the photon beam asymmetry Σ for the reactions γ⃗p→π⁰p and γ⃗p→ηp from the GlueX experiment using a 9 GeV linearly-polarized, tagged photon beam incident on a liquid hydrogen target in Jefferson Lab's Hall D. The asymmetries, measured as a function of the proton momentum transfer, possess greater precision than previous π⁰ measurements, and are the first η measurements in this energy regime. The results are compared with theoretical predictions based on t-channel, quasi-particle exchange and constrain the axial-vector component of the neutral meson production mechanism in these models.