{"paper":{"title":"Neutral pion threshold production at Q^2=0.05 GeV^2/c^2 and Chiral Perturbation Theory","license":"","headline":"","cross_cats":[],"primary_cat":"nucl-ex","authors_text":"Arnd Liesenfeld, Aron M. Bernstein, Axel Wagner, Dagmar Baumann, G\\\"unther Rosner, Harald Merkel, Hartmut Schmieden, Ingo Ewald, Jan M. Friedrich, J\\\"org Bermuth, J\\\"org Friedrich, Klaus Werner Krygier, Klemen Bohinc, Marcello M. Pavan, Marco Kahrau, Markus Weis, Matthias Ding, Michael Kohl, Michael Kuss, Michael O. Distler, Michael Seimetz, Milan Potokar, Norbert Clawiter, Pascal Merle, Peter Bartsch, Peter Jennewein, Ralph B\\\"ohm, Reiner Neuhausen, Rory A. Miskimen, Sabine Derber, Simon \\v{S}irca, Thomas Pospischil, Thomas Walcher, Ulrich M\\\"uller","submitted_at":"2001-08-20T14:50:59Z","abstract_excerpt":"New data are presented on the p(e,e'p)\\pi^0 reaction at threshold at a four-momentum transfer of Q^2=0.05 GeV^2/c^2. The data were taken with the three-spectrometer setup of the A1 Collaboration at the Mainz Microtron MAMI. The complete center of mass solid angle was covered up to a center of mass energy of 4 MeV above threshold. Combined with measurements at three different values of the virtual photon polarization \\epsilon, the structure functions \\sigma_T, \\sigma_L, \\sigma_{TT}, and \\sigma_{TL} are determined. The results are compared with calculations in Heavy Baryon Chiral Perturbation Th"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"nucl-ex/0108020","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"}