On the pole content of coupled channels chiral approaches used for the $\bar{K}N$ system

Understand

Several theoretical groups describe the antikaon-nucleon interaction at low energies within approaches based on the chiral SU(3) dynamics and including next-to-leading order contributions.

• We present a comparative analysis of the pertinent models and discuss in detail their pole contents.
• It is demonstrated that the approaches lead to very different predictions for the $K^{-}p$ amplitude extrapolated to subthreshold energies as well as for the $K^{-}n$ amplitude.
• The origin of the poles generated by the models is traced to the so-called zero coupling limit, in which the inter-channel couplings are switched off.