ABC Effect and Resonance Structure in the Double-Pionic Fusion to $^3$He
Abstract
Exclusive and kinematically complete measurements of the double pionic fusion to He have been performed in the energy region of the so-called ABC effect, which denotes a pronounced low-mass enhancement in the -invariant mass spectrum. The experiments were carried out with the WASA detector setup at COSY. Similar to the observations in the basic reaction and in the He reaction, the data reveal a correlation between the ABC effect and a resonance-like energy dependence in the total cross section. Differential cross sections are well described by the hypothesis of resonance formation during the reaction process in addition to the conventional -channel mechanism. The deduced resonance width can be understood from collision broadening due to Fermi motion of the nucleons in initial and final nuclei.
Keywords
Cite
@article{arxiv.1408.5744,
title = {ABC Effect and Resonance Structure in the Double-Pionic Fusion to $^3$He},
author = {P. Adlarson and W. Augustyniak and W. Bardan and M. Bashkanov and F. S. Bergmann and M. Berłowski and H. Bhatt and A. Bondar and M. Büscher and H. Calén and I. Ciepał and H. Clement and D. Coderre and E. Czerwiński and K. Demmich and E. Doroshkevich and R. Engels and A. Erven and W. Erven and W. Eyrich and P. Fedorets and K. Föhl and K. Fransson and F. Goldenbaum and P. Goslawski and A. Goswami and K. Grigoryev and C. --O. Gullström and F. Hauenstein and L. Heijkenskjöld and V. Hejny and B. Höistad and N. Hüsken and L. Jarczyk and T. Johansson and B. Kamys and G. Kemmerling and F. A. Khan and A. Khoukaz and D. A. Kirillov and S. Kistryn and H. Kleines and B. Kłos and W. Krzemień and P. Kulessa and A. Kupść and A. Kuzmin and K. Lalwani and D. Lersch and B. Lorentz and A. Magiera and R. Maier and P. Marciniewski and B. Mariański and M. Mikirtychiants and H. -P. Morsch and P. Moskal and H. Ohm and I. Ozerianska and E. Perez del Rio and N. M. Piskunov and P. Podkopał and D. Prasuhn and A. Pricking and D. Pszczel and K. Pysz and A. Pyszniak and J. Ritman and A. Roy and Z. Rudy and S. Sawant and S. Schadmand and T. Sefzick and V. Serdyuk and B. Shwartz and R. Siudak and T. Skorodko and M. Skurzok and J. Smyrski and V. Sopov and R. Stassen and J. Stepaniak and E. Stephan and G. Sterzenbach and H. Stockhorst and H. Ströher and A. Szczurek and A. Täschner and A. Trzciński and R. Varma and G. J. Wagner and M. Wolke and A. Wrońska and P. Wüstner and P. Wurm and A. Yamamoto and L. Yurev and J. Zabierowski and M. J. Zieliński and A. Zink and J. Złomańczuk and P. Żuprański and M. Żurek},
journal= {arXiv preprint arXiv:1408.5744},
year = {2015}
}