Sign ambiguity in the K Sigma channel

Abstract

Ambiguities of the signs of $N\to \Sigma K$ coupling constants are studied in a multichannel partial wave analysis of a large body of pion and photo-induced reactions. It is shown that the signs are not free from some ambiguities, and further experimental data are needed. Data on the reactions ${\pi }^{+}p\to {\Sigma }^{+}{K}^{+}$ and $\gamma p\to K^{+}{\Sigma }^0$ define rather well the isospin 3/2 contributions to these channels. However the lack of information on polarization observables for the reactions ${\pi }^{-}p\to {\Sigma }^0{K}^0$, ${\pi }^{-}p\to {\Sigma }^{-}{K}^{+}$ and $\gamma p\to K^0{\Sigma }^{+}$ does not allow us to fix uniquely the signs of $N\to \Sigma K$ coupling constants. As a consequence, also the contributions of nucleon resonances to these channels remain uncertain.

Comments: 8 pages, 12 figures