{"paper":{"title":"Measurement of the beam-helicity asymmetry in photoproduction of $\\pi^{0}\\eta$ pairs on carbon, aluminum, and lead","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"nucl-ex","authors_text":"A. Braghieri, A. Denig, A. Fix, A. K\\\"aser, A. Lazarev, A. Mushkarenkov, A. Neganov, A. Neiser, A. Powell, A. Sarty, A. Thiel, A. Thomas, B. Krusche, B. Strandberg, C. Collicott, C. Mullen, C. Sfienti, D. G. Middleton, D. Hornidge, D. I. Glazier, D. M. Manley, D. Paudyal, D. P. Watts, D. Werthm\\\"uller, E. J. Downie, E. Mornacchi, E. Rickert, F. Afzal, F. Cividini, G. M. Gurevich, G. M. Huber, G. Ron, H. J. Arends, I. Gorodnov, I. I. Strakovsky, I. J. D. MacGregor, I. Keshelashvili, I. Supek, J. C. McGeorge, J. R. M. Annand, J. Wettig, K. Altangerel, K. Bantawa, K. Livingston, K. Spieker, L. Heijkenskj\\\"old, L. V. Fil'kov, L. Witthauer, M. Bashkanov, M. Biroth, M. Dieterle, M. G\\\"unther, M. I. Ferretti Bondy, M. Korolija, M. Oberle, M. Ostrick, M. Thiel, M. Unverzagt, M. Wolfes, N. K. Walford, N. S. Borisov, N. Zachariou, O. Steffen, P. Achenbach, P. Adlarson, P. Aguar-Bartolom\\'e, P. B. Otte, P. Drexler, P. Pedroni, P. P. Martel, R. Beck, R. Kondratiev, R. MacRae, R. Miskimen, S. Abt, S. Cherepnya, S. Costanza, S. Gardner, S. Garni, S. Kay, S. Lutterer, S. Prakhov, S. Wagner, Th. Strub, T. Rostomyan, V. L. Kashevarov, V. Sokhoyan, W. Gradl, W. J. Briscoe, Yu. A. Usov, Z. Ahmed","submitted_at":"2019-06-29T16:26:32Z","abstract_excerpt":"The beam-helicity asymmetry was measured, for the first time, in photoproduction of $\\pi^{0}\\eta$ pairs on carbon, aluminum, and lead, with the A2 experimental setup at MAMI. The results are compared to an earlier measurement on a free proton and to the corresponding theoretical calculations. The Mainz model is used to predict the beam-helicity asymmetry for the nuclear targets. The present results indicate that the photoproduction mechanism for $\\pi^{0}\\eta$ pairs on nuclei is similar to photoproduction on a free nucleon. This process is dominated by the $D_{33}$ partial wave with the $\\eta\\D"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1907.00232","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/1907.00232/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"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"}