Differential cross sections, photon beam asymmetries, and spin density matrix elements of omega photoproduction off the proton at E-gamma=1.3-2.4 GeV

Abstract

For the reaction gamma p -> omega p, 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 Sigma and polarized spin density matrix elements rho(1)(1-1) over a wide angular range, especially above the total energy of about 2 GeV for the first time. The measured p(1-1)(1) indicates the dominance of s-channel resonances even at higher energies. The Sigma 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.