Essential cluster "K⁻pp" studied with a coupled-channel Complex Scaling Method + Feshbach method

We have investigated an essential cluster "K⁻pp", which is the simplest system of kaonic nuclei, with a coupled-channel Complex Scaling Method (ccCSM). Combining the ccCSM with Feshbach method we can handle a coupled-channel problem effectively as a singlechannel problem. As a result of a study of the K⁻pp with the ccCSM+Feshbach method using an energy-dependent chiral-theory based potential, it is found that the K⁻pp is shallowly bound with the binding energy of around 20-35 MeV. The mesonic decay width is rather dependent on the interaction parameters and ansatz; the half decay width is ranging from 20 to 65 MeV.