Chiral SU(3) dynamics and the quasibound K^-pp cluster

The prototype of a Kbar nuclear cluster, K^-pp, has been investigated using effective KbarN potentials based on chiral SU(3) dynamics. Variational calculation shows a bound state solution with shallow binding energy B(K^-pp)=20 \pm 3 MeV and broad mesonic decay width \Gamma(KbarNN -> \pi Y N)=40 - 70 MeV. The KbarN(I=0) pair in the K^-pp system exhibits a similar structure as the \Lambda(1405). We have also estimated the dispersive correction, p-wave KbarN interaction, and two-nucleon absorption width.