{"paper":{"title":"The reaction ${n} {p} \\to {p} {p} \\pi^{-}$ from threshold up to 570 MeV","license":"","headline":"","cross_cats":["nucl-th"],"primary_cat":"nucl-ex","authors_text":"(2) Paul-Scherrer-Institute, (3) Universita Karlova, 4), 4) ((1) University of Freiburg, (4) JINR, (5) DAPNIA/SPP, A. Janata (4), CEA/Saclay), Dubna, F.H. Heinsius (1), F. Lehar (5), H. Lacker (1), H. Schmitt (1), J. Franz (1), Jr. (4), K. K\\\"onigsmann (1), M. Daum (2), M. Finger, M. Finger (3, M. Slune\\v{c}ka (3, Prague, P. Sereni (1), W. Schweiger (1)","submitted_at":"2001-08-07T10:22:50Z","abstract_excerpt":"The reaction ${n} {p} \\to {p} {p} \\pi^{-}$ has been studied in a kinematically complete measurement with a large acceptance time-of-flight spectrometer for incident neutron energies between threshold and 570 MeV. The proton-proton invariant mass distributions show a strong enhancement due to the pp($^{1}{S}_{0}$) final state interaction. A large anisotropy was found in the pion angular distributions in contrast to the reaction ${p}{p} \\to {p}{p} \\pi^{0}$. At small energies, a large forward/backward asymmetry has been observed. From the measured integrated cross section $\\sigma({n}{p} \\to {\\rm "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"nucl-ex/0108008","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"}