{"paper":{"title":"First study of \\eta_c, \\eta(1760) and X(1835) production via \\eta'\\pi^+\\pi^- final states in two-photon collisions","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"hep-ex","authors_text":"A. Chen, A. Ishikawa, A. Kuzmin, A. M. Bakich, A. Vinokurova, B. D. Yabsley, Belle Collaboration: C.C. Zhang, B. G. Cheon, B. R. Ko, B. Shwartz, C. Kiesling, C. P. Shen, C. Schwanda, C. Z. Yuan, D. M. Asner, D. Matvienko, D. Santel, E. Nakano, E. Solovieva, G. Pakhlova, G. Varner, H. Aihara, H. Hayashii, H. J. Hyun, H. K. Park, H. Nakazawa, H. O. Kim, H. Park, H. Sahoo, I. Tikhomirov, J. Dalseno, J. G. Shiu, J. Li, J. Libby, K. Belous, K. Chilikin, K. Inami, K. M. Williams, L. E. Piilonen, M. Bischofberger, M. Danilov, M. E. Sevior, M. Feindt, M. Iwabuchi, M. J. Kim, M. Nakao, M. Petri\\v{c}, M. R\\\"ohrken, M. Shapkin, M. Stari\\v{c}, M. Sumihama, M. Uchida, N. Gabyshev, O. Schneider, P. Kody\\v{s}, P. Krokovny, P. Pakhlov, P. Smerkol, P. Wang, R. Chistov, R. Louvot, R. Mizuk, R. Pestotnik, S. Eidelman, S. Korpar, S. L. Olsen, S. McOnie, S. Nishida, S. Okuno, S. Ryu, S. Stani\\v{c}, S. Uehara, S. Uno, T. A. Shibata, T. Aushev, T. E. Browder, T. Iijima, T. Julius, T. Ohshima, T. Sanuki, T. Sumiyoshi, T. Uglov, V. Gaur, V. Shebalin, V. Vorobyev, V. Zhulanov, W. S. Hou, X. L. Wang, Y. Ban, Y. Choi, Y. Horii, Y. J. Kim, Y. L. Han, Y. Liu, Y. M. Goh, Y. Sakai, Y.-S. Sohn, Y. Unno, Y. Watanabe, Y. Yamashita, Z. Natkaniec, Z. P. Zhang, Z. Q. Liu","submitted_at":"2012-06-22T09:09:33Z","abstract_excerpt":"The invariant mass spectrum of the \\eta' \\pi^+ \\pi^- final state produced in two-photon collisions is obtained using a 673 fb^{-1} data sample collected in the vicinity of the \\Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e^+e^- collider. We observe a clear signal of the \\eta_c and measure its mass and width to be M(\\eta_c)=(2982.7 +- 1.8(stat) +- 2.2(syst) +- 0.3(model)) MeV/c^2 and \\Gamma(\\eta_c) = (37.8^{+5.8}_{-5.3}(stat) +- 2.8(syst) +- 1.4(model)) MeV/c^2. The third error is an uncertainty due to possible interference between the \\eta_c and a non-resonant c"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1206.5087","kind":"arxiv","version":2},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}