Exotic quark structure of Λ(1405) in QCD sum rule

AbstractA new analysis is performed in QCD sum rule for the lightest negative parity baryon Λ(1405). Mixings of three-quark and five-quark Fock components are taken into account. Terms containing up to dimension 12 condensates are computed in the operator product expansion. It is found that the sum rule gives much stronger coupling of Λ∗ to the five-quark operator so that the five-quark components occupy about 90% of Λ(1405)