Light-quark contributions to the magnetic form factor of the Lambda(1405)

TL;DR

This study uses lattice QCD to analyze light-quark contributions to the Lambda(1405) magnetic form factor, supporting its interpretation as an antikaon-nucleon molecular state.

Contribution

It provides the first lattice QCD calculation of light-quark contributions to the Lambda(1405) magnetic form factor, confirming its molecular structure.

Findings

Light-quark contributions support the KN molecular interpretation.

Connected contributions relate to nucleon magnetic form factors.

Results confirm the exotic molecular structure of Lambda(1405).

Abstract

In a recent study of the Lambda(1405), the suppression of the strange-quark contribution to the magnetic form factor was interpreted as the discovery of a dominant antikaon-nucleon composition for this low-lying state. We confirm this result by calculating the light u- and d-quark contributions to the Lambda(1405) magnetic form factor in lattice QCD in order to determine the extent to which their contributions support this exotic molecular description. Drawing on the recent graded-symmetry approach for the flavor-singlet components of the Lambda(1405), the separation of connected and disconnected contributions is performed in both the flavor-octet and singlet representations. The relationship between light-quark contributions to the Lambda(1405) magnetic form factor and the connected contributions of the nucleon magnetic form factors is established and compared with lattice calculations of the same quantities, confirming the KN molecular structure of the Lambda(1405) in lattice QCD.