1304.3561 (WASA-at-COSY Collaboration et al.)

Investigation of the dd -> 3He n π0 reaction with WASA-at-COSY    [PDF]

WASA-at-COSY Collaboration, :, P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, F. S. Bergmann, M. Berłowski, H. Bhatt, M. Büscher, H. Calén, I. Ciepał, H. Clement, D. Coderre, E. Czerwiński, K. Demmich, E. Doroshkevich, R. Engels, W. Erven, W. Eyrich, P. Fedorets, K. Föhl, K. Fransson, F. Goldenbaum, P. Goslawski, A. Goswami, K. Grigoryev, C. --O. Gullström, C. Hanhart, F. Hauenstein, L. Heijkenskjöld, V. Hejny, F. Hinterberger, M. Hodana, B. Höistad, A. Jany, B. R. Jany, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, F. A. Khan, A. Khoukaz, D. A. Kirillov, S. Kistryn, J. Klaja, H. Kleines, B. Kłos, M. Krapp, W. Krzemień, P. Kulessa, A. Kupść, K. Lalwani, D. Lersch, L. Li, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Mariański, M. Mikirtychiants, H. --P. Morsch, P. Moskal, B. K. Nandi, H. Ohm, I. Ozerianska, E. Perez del Rio, N. M. Piskunov, P. Pluciński, P. Podkopał, D. Prasuhn, A. Pricking, D. Pszczel, K. Pysz, A. Pyszniak, C. F. Redmer, J. Ritman, A. Roy, Z. Rudy, S. Sawant, A. Schmidt, S. Schadmand, T. Sefzick, V. Serdyuk, N. Shah, M. Siemaszko, R. Siudak, T. Skorodko, M. Skurzok, J. Smyrski, V. Sopov, R. Stassen, J. Stepaniak, E. Stephan, G. Sterzenbach, H. Stockhorst, H. Ströher, A. Szczurek, T. Tolba, A. Trzciński, R. Varma, G. J. Wagner, W. W\keglorz, M. Wolke, A. Wrońska, P. Wüstner, P. Wurm, A. Yamamoto, X. Yuan, J. Zabierowski, C. Zheng, M. J. Zieliński, W. Zipper, J. Złomańczuk, P. Żuprański, M. Żurek

An exclusive measurement of the dd -> 3He n \pi 0 reaction was carried at a beam momentum of p = 1.2 GeV/c using the WASA-at-COSY facility. For the first time data on the total cross section as well as differential distributions were obtained. The data are described with a phenomenological approach based on a combination of a quasi-free model and a partial wave expansion for three-body reaction. The total cross section is found to be \sigma(tot) = (2.89 +- 0.01(stat) +- 0.06(sys) +- 0.29(norm)) \mu b. The contribution of the quasi-free processes (with the neutron being target or beam spectator) accounts for 38% of the total cross section and dominates the differential distributions in specific regions of the phase space. The remaining part of the cross section can be described within a partial wave decomposition indicating the significance of p-wave contributions in the final state.

View original: http://arxiv.org/abs/1304.3561