Partial wave analysis of the reaction p(3.5GeV)+p→pK+Λ to search for the "ppK-" bound state

Agakishiev, G.; Arnold, O.; Belver, D.; Belyaev, A.; Berger Chen, J. C.; Blanco, A.; Böhmer, M.; Boyard, J. L.; Cabanelas, P.; Chernenko, S.; Dybczak, A.; Epple, E.; Fabbietti, L.; Fateev, O.; Finocchiaro, P; Fonte, P.; Friese, J.; Fröhlich, I.; Galatyuk, T.; Garzón, J. A.; Gernhäuser, R.; Göbel, K.; Golubeva, M.; González Díaz, D.; Guber, F.; Gumberidze, M.; Heinz, T.; Hennino, T.; Holzmann, R.; Ierusalimov, A.; Iori, I.; Ivashkin, A.; Jurkovic, M.; Kämpfer, B.; Karavicheva, T.; Koenig, I.; Koenig, W.; Kolb, B. W.; Kornakov, G.; Kotte, R.; Krása, A.; Krizek, F.; Krücken, R.; Kuc, H.; Kühn, W.; Kugler, A.; Kunz, T.; Kurepin, A.; Ladygin, V.; Lalik, R.; Lapidus, K.; Lebedev, A.; Lopes, L.; Lorenz, M.; Maier, L.; Mangiarotti, A.; Markert, J.; Metag, V.; Michel, J.; Müntz, C.; Münzer, R.; Naumann, L.; Pachmayer, Y. C.; Palka, M.; Parpottas, Y.; Pechenov, V.; Pechenova, O.; Pietraszko, J.; Przygoda, W.; Ramstein, B.; Reshetin, A.; Rustamov, A.; Sadovsky, A.; Salabura, P.; Schmah, A.; Schwab, E.; Siebenson, J.; Sobolev, Y. U. G.; Spataro, Stefano Giovanni; Spruck, B.; Ströbele, H.; Stroth, J.; Sturm, C.; Tarantola, A.; Teilab, K.; Tlusty, P.; Traxler, M.; Tsertos, H.; Vasiliev, T.; Wagner, V.; Weber, M.; Wendisch, C.; Wüstenfeld, J.; Yurevich, S.; Zanevsky, Y.; Sarantsev, A. V.

doi:10.1016/j.physletb.2015.01.032

Employing the Bonn-Gatchina partial wave analysis framework (PWA), we have analyzed HADES data of the reaction p(3.5 GeV) + p -> pK(+) Lambda. This reaction might contain information about the kaonic cluster "ppK(-)" (with quantum numbers J(P)=0(-) and total isospin I=1/2) via its decay into p Lambda. Due to interference effects in our coherent description of the data, a hypothetical (K) over bar NN(or, specifically "ppK-") cluster signal need not necessarily show up as a pronounced feature (e.g. a peak) in an invariant mass spectrum like p Lambda. Our PWA analysis includes a variety of resonant and non-resonant intermediate states and delivers a good description of our data (various angular distributions and two-hadron invariant mass spectra) without a contribution of a (K) over bar NN cluster. At a confidence level of CLs=95% such a cluster cannot-contribute more than 2-12% to the total cross section with a pK(+) Lambda final state, which translates into a production cross-section between 0.7 mu b and 4.2 mu b, respectively. The range of the upper limit depends on the assumed cluster mass, width and production process.