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

## TL;DR

This paper investigates the nature of the $ ext{Lambda}(1405)$ particle, calculating its mass and residue using QCD sum rules to determine if it is a hybrid baryon or an excited ordinary baryon.

## Contribution

The study provides the first QCD sum rule calculations of the $ ext{Lambda}(1405)$ as both a hybrid and an excited baryon, offering insights into its internal structure.

## Key findings

- Mass results support the hybrid baryon interpretation.
- Residue calculations aid in understanding decay properties.
- Comparison with experimental data favors the hybrid model.

## 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 $\Lambda(1405)$ 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.