Separable potential model for K- N interactions at low energies

The effective separable meson-baryon potentials are constructed to match the equivalent chiral amplitudes up to the second order in external meson momenta. We fit the model parameters (low-energy constants) to the threshold and low-energy K- p data. In the process, the K--proton bound-state problem is solved exactly in the momentum space and the 1s level characteristics of the kaonic hydrogen are computed simultaneously with the available low-energy K- p cross-sections. The model is also used to describe the pi Sigma mass spectrum and the energy dependence of the K- n amplitude.