Kaon pair production close to threshold

The total cross section of the reaction pp→ppK+K− has been measured at excess energies Q=10MeV and 28 MeV with the magnetic spectrometer COSY-11. The new data show a significant enhancement of the total cross section compared to pure phase space expectations or calculations within a one boson exchange model. In addition, we present invariant mass spectra of two particle subsystems. While the K+K− system is rather constant for different invariant masses, there is an enhancement in the pK− system towards lower masses which could at least be partially connected to the influence of the Λ(1405) resonance.