{"paper":{"title":"Hard Two-Photon Contribution to Elastic Lepton-Proton Scattering: Determined by the OLYMPUS Experiment","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"nucl-ex","authors_text":"A. Avetisyan, A. Izotov, A. Kiselev, A. Krivshich, A. Movsisyan, A. Schmidt, A. Thiel, A. Winnebeck, B. Gl\\\"aser, B. Seitz, B.S. Henderson, Ch. Funke, C. O'Connor, C. Vidal, D. Khaneft, D.K. Hasell, D. Lenz, D. Rodr\\'iguez Pi\\~neiro, D. Veretennikov, E. Cisbani, E. Ihloff, F. Brinker, F. Maas, G. Ciullo, G. Elbakian, G. Gavrilov, G. Karyan, G. Rosner, H. Marukyan, H. Vardanyan, I. Lehmann, J. Bessuille, J.C. Bernauer, J. Diefenbach, J. Hauschildt, J. Kelsey, J.R. Calarco, K. Dow, L.D. Ice, M. Contalbrigo, M. Kohl, M. Murray, M. Statera, N. Akopov, N. G\\\"orrissen, O. Ates, O. Miklukho, P.D. Eversheim, Ph. Hoffmeister, P. Klassen, P. Lenisa, R. Alarcon, R. Beck, R. De Leo, R.G. Milner, R. Kaiser, R. Perez Benito, R. Perrino, R.P. Redwine, R. Russell, S. Belostotski, S. Frullani, S. Lumsden, T.W. Donnelly, U. Schneekloth, V. Carassiti, V. Yeganov, Y. Holler, Y. Ma, Y. Naryshkin","submitted_at":"2016-11-15T03:14:35Z","abstract_excerpt":"The OLYMPUS collaboration reports on a precision measurement of the positron-proton to electron-proton elastic cross section ratio, $R_{2\\gamma}$, a direct measure of the contribution of hard two-photon exchange to the elastic cross section. In the OLYMPUS measurement, 2.01~GeV electron and positron beams were directed through a hydrogen gas target internal to the DORIS storage ring at DESY. A toroidal magnetic spectrometer instrumented with drift chambers and time-of-flight scintillators detected elastically scattered leptons in coincidence with recoiling protons over a scattering angle range"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1611.04685","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"}