{"paper":{"title":"Delta Delta Excitation in Proton-Proton Induced pi0pi0 Production","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"nucl-ex","authors_text":"A. Kupsc, A. Povtorejko, A. Yamamoto, B. Hoistad, B. Morosov, B. Shwartz, C. Ekstroem, C. Pauly, D. Bogoslawsky, E. Doroshkevich, E. Jiganov, F. Kren, G. Ivanov, G.J. Wagner, H. Calen, H. Clement, H. Petren, I. Koch, J. Stepaniak, J. Zabierowski, J. Zlomanczuk, K. Fransson, K. Schoenning, L. Demiroers, L. Gustafsson, M. Bashkanov, M. Jacewicz, M. Wolke, O. Khakimova, P. Marciniewski, P. Thoerngren-Engblom, R.J.M.Y. Ruber, R. Meier, S. Keleta, S. Kullander, T. Johansson, T. Skorodko, V. Tikhomirov, W. Scobel, Y. Petukhov","submitted_at":"2010-07-02T17:16:55Z","abstract_excerpt":"Exclusive measurements of the $pp \\to pp\\pi^0\\pi^0$ reaction have been performed at CELSIUS/WASA at energies from threshold up to $T_p$ = 1.3 GeV. Total and differential cross sections have been obtained. Here we concentrate on energies $T_p \\ge$ 1 GeV, where the $\\Delta\\Delta$ excitation becomes the leading process. No evidence is found for a significant ABC effect beyond that given by the conventional $t$-channel $\\Delta\\Delta$ excitation. This holds also for the double-pionic fusion to the quasibound $^2$He. The data are compared to model predictions, which are based on both pion and $\\rho$"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1007.0405","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"}