{"paper":{"title":"First measurement of proton's charge form factor at very low $Q^2$ with initial state radiation","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["hep-ex"],"primary_cat":"nucl-ex","authors_text":"A. B. Weber, A. Denig, A. Esser, A. Tyukin, B. S. Schlimme, C. Sfienti, D. Bosnar, D. G. Middleton, F. Schulz, H. Fonvieille, H. Merkel, I. Fri\\v{s}\\v{c}i\\'c, J. Beri\\v{c}i\\v{c}, J. C. Bernauer, J. M. Friedrich, J. Pochodzalla, K. Griffioen, L. Correa, L. Debenjak, L. Nungesser, M. Cardinali, M. Hoek, M. I. Ferretti Bondy, M. Mihovilovi\\v{c}, M. O. Distler, M. Rohrbeck, M. Schoth, M. Thiel, M. Vanderhaeghen, M. Weinriefer, P. Achenbach, R. B\\\"ohm, S. Kegel, S. S\\'anchez Majos, S. \\v{S}irca, S. \\v{S}tajner, T. Beranek, U. M\\\"uller, Y. Kohl","submitted_at":"2016-12-20T15:28:25Z","abstract_excerpt":"We report on a new experimental method based on initial-state radiation (ISR) in e-p scattering, in which the radiative tail of the elastic e-p peak contains information on the proton charge form factor ($G_E^p$) at extremely small $Q^2$. The ISR technique was validated in a dedicated experiment using the spectrometers of the A1-Collaboration at the Mainz Microtron (MAMI). This provided first measurements of $G_E^p$ for $0.001\\leq Q^2\\leq 0.004 (GeV/c)^2$."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1612.06707","kind":"arxiv","version":1},"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"}