{"paper":{"title":"First measurement of coherent $\\phi$-meson photoproduction from helium-4 near threshold","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"nucl-ex","authors_text":"A. O. Tokiyasu, C. Rangacharyulu, D. S. Ahn, E. A. Strokovsky, H. Fujimura, H. Kawai, H. Kohri, H. Shimizu, J. K. Ahn, J. Y. Chen, K. Hicks, K. Mizutani, K. Suzuki, LEPS Collaboration: T. Hiraiwa, M. Miyabe, M. Niiyama, M. Oka, M. Sumihama, M. Uchida, M. Yosoi, N. Muramatsu, P. J. Lin, S. Dat\\'e, S. Fukui, S. H. Hwang, S. Y. Ryu, T. Hotta, T. Ishikawa, T. Nakano, T. Ohta, T. Saito, T. Sawada, T. Tomioka, T. Tsunemi, T. Yorita, W. C. Chang, Y. Kato, Y. Kon, Y. Maeda, Y. Morino, Y. Nakatsugawa, Y. Nozawa, Y. Ohashi, Y. Sugaya","submitted_at":"2017-11-03T10:34:24Z","abstract_excerpt":"The differential cross sections and decay angular distributions for coherent $\\phi$-meson photoproduction from helium-4 have been measured for the first time at forward angles with linearly polarized photons in the energy range $E_{\\gamma} = \\text{1.685-2.385 GeV}$. Thanks to the target with spin-parity $J^{P} = 0^{+}$, unnatural-parity exchanges are prohibited, and thus natural-parity exchanges can be investigated clearly. The decay asymmetry with respect to photon polarization is shown to be very close to the maximal value. This ensures the dominance ($> 94\\%$) of natural-parity exchanges in"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1711.01095","kind":"arxiv","version":3},"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"}