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.
ASJC Scopus subject areas
- Nuclear and High Energy Physics