Mass and residue of Lambda(1405) as hybrid and excited ordinary baryon

Abstract

The nature of the Lambda(1405) has been a puzzle for decades, whether it is a standard three-quark baryon, a hybrid baryon or a baryon-meson molecule. More information on the decay channels of this particle and its strong, weak and electromagnetic interactions with other hadrons is needed to clarify its internal organization. The residue of this particle is one of the main inputs in investigation of its decay properties in many approaches. We calculate the mass and residue of the Lambda(1405) state in the context of QCD sum rules considering it as a hybrid baryon with three-quark-one-gluon content as well as an excited ordinary baryon with quantum numbers I(J(P)) = 0(1/2(-)). The comparison of the obtained results on the mass with the average experimental value presented in PDG allows us to interpret this state as a hybrid baryon.