Measurement of the photon beam asymmetry Σ for γ + p → K+Σ0 at Eγ = 8.5 GeV in GlueX

Abstract

We present measurements of the photon beam asymmetry Σ for the reaction γp → K+Σ0(1193) using the GlueX experiment in Jefferson Lab's Hall D. Data were collected using a linearly polarized photon beam with energy range 8.2-8.8 GeV incident on a liquid hydrogen target. Asymmetries are measured as functions of Mandelstam variables −t and −u. These are the first fully exclusive measurements of the photon beam asymmetry Σ in this reaction at high energies with detection of all final state particles. In the t-channel, results show that the reaction is dominated by the natural-parity exchange of presumably the K*(892) meson, as predicted by theoretical models. Results obtained for the u-channel are consistent with an intermediate baryon exchange mechanism predicted by theoretical models.