Differential cross sections, photon beam asymmetries, and spin density matrix elements of ω photoproduction off the proton at Eγ=1.3−2.4 GeV

Abstract

For the reaction γp→ωp, differential cross sections, photon beam asymmetries, and spin density matrix elements have been measured in the BGOegg experiment at the SPring-8 LEPS2 beamline by using a large acceptance electromagnetic calorimeter. A 1.3–2.4 GeV photon beam with high linear polarization has enabled a precision measurement of photon beam asymmetries Σ and polarized spin density matrix elements ρ1−11 over a wide angular range, especially above the total energy of about 2 GeV for the first time. The measured ρ1−11 indicates the dominance of s-channel resonances even at higher energies. The Σ values at backward angles are not reproduced by the existing partial-wave analysis in the highest-energy region, providing new constraints to the contribution of nucleon resonances with high spins.Received 27 March 2020Accepted 2 July 2020DOI:https://doi.org/10.1103/PhysRevC.102.025201©2020 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasPhotonuclear reactionsQuark modelPhysical SystemsHadronsNuclear Physics