Beam asymmetry Σ for the photoproduction of η and η′ mesons at Eγ

Abstract

We report on the measurement of the beam asymmetry for the reactions γ p → pη and γ p → pη from the GlueX experiment using an 8.2-8.8-GeV linearly polarized tagged photon beam incident on a liquid hydrogen

Novel approaches in Hadron Spectroscopy

“…[544], we modeled the contribution of the φ exchange and obtained that the ratio of η and η beam asymmetries would deviate from 1 by maximum 2% in the range −t < 1 GeV 2 . This ratio, measured recently by the GlueX collaboration [553] and presented in Figure 40 (right), turned out to be compatible with unity indeed. However, uncertainties are still quite large, about 10%, and the data points are centered around a nominal value about 0.95.…”

Physics with CEBAF at 12 GeV and Future Opportunities

“…Thus, early measurements from GlueX have focused on a quantitative understanding of the meson photoproduction mechanism in this energy regime. Utilizing the linearly-polarized photon beam, beam asymmetries Σ have been measured for several single pseudoscalar mesons including the π 0 , π − , K + , η, and η over a broad range of momentum transfer, −t [207,205,206,208]. As demonstrated in Fig.…”

Measurement of beam asymmetry for π−Δ++ photoproduction on the proton at Eγ=8.5Adhikari1, Akondi2, Ali3 et al. 2021Phys. Rev. CSelf Cite6030View full textAdd to dashboardCite

“…Measurements that constrain production mechanisms at photon beam energies relevant for the GlueX experiment are sparse. Recent measurements on the photoproduction of pseudoscalar mesons [5][6][7] have begun to provide insight into into production mechanisms. In this paper, we seek to extend this understanding by measuring the beam asymmetry ⌃ for the charge-exchange re-action~ p !…”