1. Importance of d-wave contributions in the charge symmetry breaking reaction dd→4Heπ0
- Author
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Adlarson, P., Augustyniak, W., Clement, H., Czerwiński, E., Demmich, K., Engels, Ralf W., Erven, A., Erven, W., Eyrich, W., Fedorets, P., Föhl, K., Fransson, K., Bardan, W., Goldenbaum, F., Goswami, A., Grigoryev, K., Gullström, C.-O., Hanhart, C., Heijkenskjöld, L., Hejny, V., Hüsken, N., Jarczyk, L., Johansson, T., Bashkanov, M., Kamys, B., Kemmerling, G., Khatri, G., Khoukaz, A., Khreptak, O., Kirillov, D. A., Kistryn, S., Kleines, H., Kłos, B., Krzemień, W., Bergmann, F. S., Kulessa, P., Kupść, A., Kuzmin, A., Lalwani, K., Lersch, D., Lorentz, B., Magiera, A., Maier, R., Marciniewski, P., Mariański, B., Berłowski, M., Morsch, H.-P., Moskal, P., Ohm, H., Parol, W., Perez del Rio, E., Piskunov, N. M., Prasuhn, D., Pszczel, D., Pysz, K., Pyszniak, A., Bondar, A., Ritman, J., Roy, A., Rudy, Z., Rundel, O., Sawant, S., Schadmand, S., Schätti-Ozerianska, I., Sefzick, T., Serdyuk, V., Shwartz, B., Büscher, M., Sitterberg, K., Skorodko, T., Skurzok, M., Smyrski, J., Sopov, V., Stassen, R., Stepaniak, J., Stephan, E., Sterzenbach, G., Stockhorst, H., Calén, H., Ströher, H., Szczurek, A., Trzciński, A., Wolke, M., Wrońska, A., Wüstner, P., Yamamoto, A., Zabierowski, J., Zieliński, M. J., Złomańczuk, J., Ciepał, I., Żuprański, P., and Żurek, M.
- Subjects
charge symmetry breaking ,deuteron–deuteron interactions ,pion production ,Nuclear Theory ,ddc:530 ,High Energy Physics::Experiment ,Nuclear Experiment ,lcsh:Physics ,lcsh:QC1-999 - Abstract
This letter reports a first quantitative analysis of the contribution of higher partial waves in the charge symmetry breaking reaction dd→4Heπ0 using the WASA-at-COSY detector setup at an excess energy of Q=60MeV. The determined differential cross section can be parametrized as dσ/dΩ=a+bcos2θ⁎, where θ⁎ is the production angle of the pion in the center-of-mass coordinate system, and the results for the parameters are a=(1.55±0.46(stat)+0.32−0.8(syst))pb/sr and b=(13.1±2.1(stat)−2.7+1.0(syst))pb/sr. The data are compatible with vanishing p-waves and a sizable d-wave contribution. This finding should strongly constrain the contribution of the Δ isobar to the dd→4Heπ0 reaction and is, therefore, crucial for a quantitative understanding of quark mass effects in nuclear production reactions. Keywords: Charge symmetry breaking, Deuteron–deuteron interactions, Pion production
- Published
- 2018
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