%0 Journal Article
%T The reactions $pp\to p¦«K^+$ and $pp\to p¦²^0K^+$ near their thresholds
%A A. Gasparian
%A J. Haidenbauer
%A C. Hanhart
%A L. Kondratyuk
%A J. Speth
%J Physics
%D 1999
%I arXiv
%R 10.1016/S0370-2693(00)00412-3
%X The reactions $pp\to p\Lambda K^+$ and $pp\to p\Sigma^0K^+$ are studied near their thresholds. The strangeness production process is described by the $\pi$- and $K$ exchange mechanisms. Effects from the final state interaction in the hyperon-nucleon system are taken into account rigorously. It is found that the $\Lambda$ production is dominated by $K$ exchange whereas $K$- as well as $\pi$ exchange play an important role for the $\Sigma^0$ case. It is shown that the experimentally observed strong suppression of $\Sigma^0$ production compared to $\Lambda$ production at the same excess energy can be explained by a destructive interference between $\pi$ and $K$ exchange in the reaction $pp\to p\Sigma^0K^+$. Implications of such an interference on the reaction $pp\to n\Sigma^+K^+$ are pointed out.
%U http://arxiv.org/abs/nucl-th/9909017v3