Extracting Low-Lying Lambda Resonances Using Correlation Matrix Techniques

TL;DR

This paper demonstrates that using a variational analysis with multiple smearings in lattice QCD can effectively extract the low-lying Lambda resonance states more accurately than traditional methods.

Contribution

It introduces a correlation matrix technique with variational analysis to improve the extraction of low-lying Lambda resonances in full-QCD simulations.

Findings

Variational analysis yields lower-lying Lambda states than standard methods.

Multiple source and sink smearings enhance state extraction accuracy.

The approach is validated on PACS-CS configurations.

Abstract

The lowest-lying negative-parity state of the Lambda is investigated in (2+1)-flavour full-QCD on the PACS-CS configurations made available through the ILDG. We show that a variational analysis using multiple source and sink smearings can extract a state lying lower than that obtained by using a standard fixed smeared source and sink operator alone.