Low-energyK−-nucleon potentials and the nature of theΛ(1405)

The low-energy K¯N system is examined using a general separable and a vector-meson exchange potential. A direct fit to the data including the $K^{\mathrm{-}}$p threshold branching ratios is made in order to determine the nature of the resonance at 1405 MeV. Satisfactory fits are obtained using potential parameters within the range of expected SU(3) breaking and vertex coupling constants roughly consistent with values derived from NN analyses.