K(K)over-barN molecule state with I=1/2 and JP=1/2+ studied with a three-body calculation

A K (K) over bar N system with I = 1/2 and J(P) = 1/2(+) is investigated with nonrelativistic three-body calculations by using effective (K) over barN, K (K) over bar interactions. The (K) over barN interaction describes the Lambda (1405) as a (K) over barN molecule, and the K (K) over bar interaction is adjusted to give f(0)(980) and a0(980) states as K (K) over bar molecules. The present investigation suggests that a bound K (K) over barN state can be formed below the K (K) over barN threshold (1930 Mev) with a 90 similar to 100 MeV width of three-hadron decays, which are dominated K (K) over barN -> K pi Sigma and pi eta N. The K (K) over barN state is found to be a weakly bound hadron molecular state with a size larger than an alpha particle because of the repulsive KN interactions.