# Hyperon I: Study of the $\Lambda(1405)$

## TL;DR

This paper analyzes various low-energy experimental data related to the $ar{K}N$ system, demonstrating that the $ ext{Lambda}(1405)$} can be described with a single isoscalar spin-1/2 negative-parity pole, simplifying previous models.

## Contribution

It provides a comprehensive fit of diverse experimental data using a single pole model for the $ ext{Lambda}(1405)$, challenging more complex multi-pole interpretations.

## Key findings

- Data can be fitted with one $ ext{Lambda}(1405)$ pole
- Background contributions are significant
- Supports a simplified single-pole model

## Abstract

Low-energy data on the three charge states in $\gamma p \to K^+(\Sigma\pi)$ from CLAS at JLab, on $K^-p\to \pi^0\pi^0\Lambda$ and $\pi^0\pi^0\Sigma$ from the Crystal Ball at BNL, bubble chamber data on $K^-p\to\pi^-\pi^+\pi^{\pm}\Sigma^{\mp}$, low-energy total cross sections on $K^-$ induced reactions, and data on the $K^-p$ atom are fitted with the BnGa partial-wave-analysis program. We find that the data can be fitted well with just one isoscalar spin-1/2 negative-parity pole, the $\Lambda(1405)$, and background contributions.