Backward-angle photoproduction of ω and η′ mesons from protons in the photon energy range from 1.5 to 3.0 GeV

1Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan 2RIKEN Nishina Center for Accelerator-Based Science, Wako, Saitama 351-0198, Japan 3KEK, High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801, Japan 4Department of Physics, Kyoto University, Kyoto 606-8502, Japan 5Department of Physics, Korea University, Seoul 136-713, Korea 6Institute of Physics, Academia Sinica, Taipei 11529, Taiwan 7Japan Synchrotron Radiation Research Institute, Sayo, Hyogo 679-5143, Japan 8Wakayama Medical University, Wakayama 641-8509, Japan 9Department of Physics and Astrophysics, Nagoya University, Nagoya, Aichi 464-8602, Japan 10Department of Physics and Astronomy, Ohio University, Athens, OH 45701, USA 11Japan Atomic Energy Agency, Tokai-mura, Ibaraki 319-1195, Japan 12Research Center for Electron Photon Science, Tohoku University, Sendai, Miyagi 982-0826, Japan 13Department of Physics, Chiba University, Chiba 263-8522, Japan 14Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea 15Proton Therapy Center, Fukui Prefectural Hospital, Fukui 910-8526, Japan 16Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon SK S7N 5E2,