Pion magnetic polarisability using the background field method

TL;DR

This paper calculates the pion's magnetic polarisability using lattice QCD with background magnetic fields, introducing new methods for improved precision in understanding hadron structure.

Contribution

It introduces a novel magnetic-field dependent eigenmode projector and employs a background-field corrected fermion action for more accurate lattice QCD calculations.

Findings

Precise determination of pion magnetic polarisability.

Implementation of a new eigenmode projector improves signal quality.

Use of background-field corrected fermion action enhances calculation accuracy.

Abstract

The magnetic polarisability is a fundamental property of hadrons, which provides insight into their structure in the low-energy regime. The pion magnetic polarisability is calculated using lattice QCD in the presence of background magnetic fields. The results presented are facilitated by the introduction of a new magnetic-field dependent quark-propagator eigenmode projector and the use of the background-field corrected clover fermion action. The magnetic polarisabilities are calculated in a relativistic formalism, and the excellent signal-to-noise property of pion correlation functions facilitates precise values.