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.
@article{arxiv.nucl-ex/0402008,
title = {Energy dependence of the Lambda/Sigma0 production cross section ratio in proton proton interactions},
author = {P. Kowina and M. Wolke and H. -H. Adam and A. Budzanowski and R. Czyzykiewicz and D. Grzonka and J. Haidenbauer and M. Janusz and L. Jarczyk and B. Kamys and A. Khoukaz and K. Kilian and P. Moskal and W. Oelert and C. Piskor-Ignatowicz and J. Przerwa and C. Quentmeier and T. Rozek and R. Santo and G. Schepers and T. Sefzick and M. Siemaszko and J. Smyrski and S. Steltenkamp and A. Strzalkowski and A. Taschner and P. Winter and P. Wustner and W. Zipper},
journal= {arXiv preprint arXiv:nucl-ex/0402008},
year = {2009}
}