Energy dependence of the Lambda/Sigma0 production cross section ratio in   proton proton interactions
  The production of the Lambda and Sigma0 hyperons has been measured via the pp->pK+Lambda / Sigma0 reaction at the internal COSY-11 facility in the excess energy range between 14 and 60 MeV. The transition of the Lambda/Sigma0 cross section ratio from about 28 at Q<=13 MeV to the high energy level of about 2.5 is covered by the data showing a strong decrease of the ratio between 10 and 20 MeV excess energy.   Effects from the final state interactions in the p-Sigma0 channel seem to be much smaller compared to the p-Lambda one. Estimates of the effective range parameters are given for the N-Lambda and the N-Sigma systems. 
P. Kowina, M. Wolke, H.-H. Adam, A. Budzanowski, R. Czyzykiewicz, D.   Grzonka, J. Haidenbauer, M. Janusz, L. Jarczyk, B. Ka...