  We have investigated a prototype of kaonic nuclei, "$K^-pp$", with a
coupled-channel Complex Scaling Method (ccCSM). Combining the ccCSM with
Feshbach projection method, we can handle a coupled-channel problem effectively
as a single-channel problem. By using an energy-dependent chiral SU(3)-based
$\bar{K}N$ potential, the $K^-pp$ ($J^\pi=0^-$ and $T=1/2$) is obtained to be
shallowly bound with the binding energy of 20-30 MeV. The mesonic decay width
depends on the interaction parameters and ansatz; the decay width is ranging
from 20 to 65 MeV. In case of $J^\pi=1^-$ state, no three-body $\bar{K}NN$
resonant states are found.

Nuclear Theory;Nuclear Experiment