{"paper":{"title":"Origin of the low-mass electron pair excess in light nucleus-nucleus collisions","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. Ivashkin, A. Kugler, A. Kurepin, 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, 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. Lapidus, K. Teilab, L. Fabbietti, L. Lopes, L. Maier, L. Naumann, M. B\\\"ohmer, M. Destefanis, M. Golubeva, M. Jurkovic, M. Lorenz, M. Palka, M. Sudol, M. Traxler, M. Weber, M. Wisniowski, O. Pechenova, O. V. Fateev, P. Braun-Munzinger, P. Cabanelas, P. Finocchiaro, P. Fonte, 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, The HADES Collaboration: G. Agakishiev, T. Hennino, T. Karavicheva, T. Liu, T. Wojcik, V. Metag, V. Pechenov, V. Wagner, W. Koenig, W. K\\\"uhn, W. Przygoda, Y. C. Pachmayer, Y. Parpottas, Yu.G. Sobolev, Y. V. Zanevsky","submitted_at":"2009-10-30T15:00:06Z","abstract_excerpt":"We report measurements of electron pair production in elementary p+p and d+p reactions at 1.25 GeV/u with the HADES spectrometer. For the first time, the electron pairs were reconstructed for n+p reactions by detecting the proton spectator from the deuteron breakup. We find that the yield of electron pairs with invariant mass Me+e- > 0.15 GeV/c2 is about an order of magnitude larger in n+p reactions as compared to p+p. A comparison to model calculations demonstrates that the production mechanism is not sufficiently described yet. The electron pair spectra measured in C+C reactions are compatib"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0910.5875","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"}