K− absorption on two nucleons and ppK− bound state search in the Σ0p final state

We report the measurement of K− absorption processes in the Σ0pΣ0p final state and the first exclusive measurement of the two nucleon absorption (2NA) with the KLOE detector. The 2NA process without further interactions is found to be 9% of the sum of all other contributing processes, including absorption on three and more nucleons or 2NA followed by final state interactions with the residual nucleons. We also determine the possible contribution of the ppK− bound state to the Σ0pΣ0p final state. The yield of ppK−/Kstop− is found to be (0.044±0.009stat−0.005+0.004syst)⋅10−2 but its statistical significance based on an F-test is only 1σ.