ABC Resonance Structure in the Double-Pionic Fusion to 4He
Creators: name: Adlarson, P.
name: Augustyniak, W.
name: Bardan, W.
name: Bashkanov, M.
name: Bednarski, T.
name: Bergmann, F. S.
name: Berlowski, M.
name: Bhatt, H.
name: Brinkmann, K. T.
name: Buescher, M.
name: Calen, H.
name: Clement, H.
name: Coderre, D.
name: Czerwinski, E.
name: Demmich, K.
name: Doroshkevich, E.
name: Engels, R.
name: Erven, W.
name: Eyrich, W.
name: Fedorets, P.
name: Foehl, K.
name: Fransson, K.
name: Goldenbaum, F.
name: Goslawski, P.
name: Grigoryev, K.
name: Gullstroem, C. O.
name: Hauenstein, F.
name: Heijkenskjold, L.
name: Hejny, V.
name: Hinterberger, F.
name: Hodana, M.
name: Hoistad, B.
name: Husmann, C.
name: Jany, A.
name: Jany, B. R.
name: Jarczyk, L.
name: Johansson, T.
name: Kamys, B.
name: Kemmerling, G.
name: Khan, F. A.
name: Khoukaz, A.
name: Kistryn, S.
name: Klaja, J.
name: Kleines, H.
name: Klos, B.
name: Krzemien, W.
name: Kulessa, P.
name: Kupsc, A.
name: Lalwani, K.
name: Lersch, D.
name: Li, L.
name: Lorentz, B.
name: Magiera, A.
name: Maier, R.
name: Marciniewski, P.
name: Marianski, B.
name: Mikirtychiants, M.
name: Morsch, H. P.
name: Moskal, P.
name: Nandi, B. K.
name: Niedzwiecki, S.
name: Ohm, H.
name: Ozerianska, I.
name: Pauly, C.
name: del Rio, E. Perez
name: Petukhov, Y.
name: Plucinski, P.
name: Podkopal, P.
name: Prasuhn, D.
name: Pricking, A.
name: Pszczel, D.
name: Pysz, K.
name: Pyszniak, A.
name: Redmer, C. F.
name: Ritman, J.
name: Roy, A.
name: Rudy, Z.
name: Sawant, S.
name: Schadmand, S.
name: Schmidt, A.
name: Serdyuk, V.
name: Shah, N.
name: Siudak, R.
name: Skorodko, T.
name: Skurzok, M.
name: Smyrski, J.
name: Sopov, V.
name: Stassen, R.
name: Stepaniak, J.
name: Sterzenbach, G.
name: Stockhorst, H.
name: Stroeher, H.
name: Szczurek, A.
name: Tolba, T.
name: Trzcinski, A.
name: Varma, R.
name: Vlasov, P.
name: Wagner, G. J.
name: Wkeglorz, W.
name: Wolke, M.
name: Wronska, A.
name: Wuestner, P.
name: Wurm, P.
name: Yamamoto, A.
name: Yuan, X.
name: Yurev, L.
name: Zabierowski, J.
name: Zheng, C.
name: Zielinski, M. J.
name: Zipper, W.
name: Zlomanczuk, J.
name: Zupranski, P.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: Exclusive and kinematically complete high-statistics measurements of the double pionic fusion reaction $dd \to ^4$He$π^0π^0$ have been performed in the energy range 0.8 - 1.4 GeV covering thus the region of the ABC effect, which denotes a pronounced low-mass enhancement in the $ππ$-invariant mass spectrum. The experiments were carried out with the WASA detector setup at COSY. Similar to the observation in the basic $pn \to d π^0π^0$ reaction, the data reveal a correlation between the ABC effect and a resonance-like energy dependence in the total cross section. The maximum occurs at m=2.37 GeV + 2$m_N$, i.e. at the same position as in the basic reaction. The observed resonance width $Γ\approx$ 160 MeV can be understood from broadening due to Fermi motion of the nucleons in initial and final nuclei together with collision damping. Differential cross sections are described equally well by the hypothesis of a $pn$ resonance formation during the reaction process.