Probing the existence of the Kaonic Nuclear Cluster "ppK-" with help of a PWA

Eliane Epple (TU München)

The ppK-, a well established state in theory, is a hot candidate for a new kind of hadronic matter formed by antikaons that are bound to nucleons.
The HADES spectrometer at GSI provides ideal conditions to test the existence of such a cluster of particles. HADES has recorded p+p collisions at a beam energy of 3.5 GeV. Out of this statistic we have analysed events where a p, K+ and Lambda have been produced in the final state.
I will discuss how these three particles are connected to the "ppK-" and how we searched for fingerprints of a possible "ppK-" production in this final state. I will, further, present the results of a partial wave analysis that lead to the establishment of an upper limit of the production cross section of kaonic nuclear bound state. Since no clear signal has been observed in our analysis, we question the observation of the "ppK-" cluster at a lower beam energy, reported by the DISTO collaboration.

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