{"paper":{"title":"Study of the quasi-free $np \\to np \\pi^+\\pi^-$ reaction with a deuterium beam at 1.25 GeV/nucleon","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"nucl-ex","authors_text":"A. Balanda, A. Blanco, A. Dybczak, A. Gil, A. Ierusalimov, A. Ivashkin, A. Kugler, A. Kurepin, A. Kurilkin, A. Mangiarotti, A. Reshetin, A. Rustamov, A. Sadovsky, A. Schmah, A. Tarantola, A.V. Belyaev, B. K\\\"ampfer, B. Michalska, B. Ramstein, B. Spruck, B.W. Kolb, C. Gilardi, C. M\\\"untz, C. Sturm, D. Belver, D. Gonz\\'alez-D\\'iaz, D. Kirschner, E. Castro, E. Morini\\`ere, E. Schwab, F. Dohrmann, F. Guber, F. Krizek, G. Agakishiev, H. Str\\\"obele, H. Tsertos, I. Fr\\\"ohlich, I. Iori, I. Koenig, J.A. Garz\\'on, J. D\\'iaz, J. Friese, J.L. Boyard, J. Markert, J.Michel, J. Mousa, J. Otwinowski, J. Pietraszko, J.S.Lange, J. Stroth, J. W\\\"ustenfeld, K. G\\\"obel, K. Lapidus, K.Teilab, L. Fabbietti, L. Lopes, L. Maier, L. Naumann, M. B\\\"ohmer, M. Destefanis, M. Golubeva, M. Gumberidze, M. Jurkovic, M. Lorenz, M. Palka, M. Traxler, M. Weber, M. Wisniowski, O. Pechenova, O.V. Fateev, P. Braun-Munzinger, P. Cabanelas, P. Finocchiaro, P. Fonte, P. Kurilkin, P.Salabura, P. Tlusty, P. Zhou, R. Gernh\\\"auser, R. Holzmann, R. Kotte, R. Kr\\\"ucken, R. Trebacz, S. Chernenko, S. Lang, S. Spataro, S. Yurevich, T. Christ, T. Galatyuk, T. Hennino, T. Karavicheva, T. Liu, T. Vasiliev, T. Wojcik, V. Ladygin, V. Metag, V.Pechenov, V. Wagner, W. Koenig, W. K\\\"uhn, W. Przygoda, Y.C. Pachmayer, Y. Parpottas, Yu.G. Sobolev, Y. Zanevsky","submitted_at":"2015-03-13T10:35:54Z","abstract_excerpt":"The tagged quasi-free $np \\to np\\pi^+\\pi^-$ reaction has been studied experimentally with the High Acceptance Di-Electron Spectrometer (HADES) at GSI at a deuteron incident beam energy of 1.25 GeV/nucleon ($\\sqrt s \\sim$ 2.42 GeV/c for the quasi-free collision). For the first time, differential distributions for $\\pi^{+}\\pi^{-}$ production in $np$ collisions have been collected in the region corresponding to the large transverse momenta of the secondary particles. The invariant mass and angular distributions for the $np\\rightarrow np\\pi^{+}\\pi^{-}$ reaction are compared with different models. "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1503.04013","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"}