$\mathrm{\Lambda }\mathbf{(}1405\mathbf{)}$ as a $\overline{K}N$ Feshbach resonance in the Skyrme model

We describe the $\mathrm{\Lambda }(1405)$ hyperon as a Feshbach resonance of a $\overline{K}N$ quasibound state coupled by a decaying channel of $\pi \mathrm{\Sigma }$ in the Skyrme model. A weakly bound $\overline{K}N$ state is generated in the laboratory frame, while the $\mathrm{\Sigma }$ hyperon as a strongly bound state of $\overline{K}N$ in the intrinsic frame. We obtain a coupling of $\overline{K}N$ and $\pi \mathrm{\Sigma }$ channels by computing a baryon matrix element of the axial current. This coupling enables the decay of the $\overline{K}N$ bound state to $\pi \mathrm{\Sigma }$. It is shown that the Skyrme model supports the $\mathrm{\Lambda }(1405)$ as a narrow Feshbach resonance.