Kaon pair production close to threshold
  The total cross section of the reaction pp->ppK+K- has been measured at excess energies Q=10 MeV 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 Lambda(1405) resonance. 
P. Winter, M. Wolke, H.-H. Adam, A. Budzanowski, R. Czyzykiewicz, D.   Grzonka, M. Janusz, L. Jarczyk, B. Kamys, A. Khoukaz,...