Chiral Corrections to Hyperon Axial Form Factors

TL;DR

This paper analyzes hyperon axial form factors using chiral perturbation theory, revealing meson pole effects and proposing lattice studies to test chiral expansion accuracy in baryons.

Contribution

It provides a comprehensive calculation of hyperon axial form factors and introduces a method to test chiral expansion effectiveness via lattice QCD, despite unknown low-energy constants.

Findings

Meson pole contributions signal chiral physics.

Chiral corrections to SU(3) symmetry predictions are calculable.

Next-to-leading order symmetry breaking predictions are made for axial charge combinations.

Abstract

We study the complete set of flavor changing hyperon axial current matrix elements at small momentum transfer. Using partially quenched heavy baryon chiral perturbation theory, we derive the chiral and momentum behavior of the axial and induced pseudoscalar form factors. The meson pole contributions to the latter posses a striking signal for chiral physics. We argue that the study of hyperon axial matrix elements enables a systematic lattice investigation of the efficacy of three flavor chiral expansions in the baryon sector. This can be achieved by considering chiral corrections to SU(3) symmetry predictions, and their partially quenched generalizations. In particular, despite the presence of eight unknown low-energy constants, we are able to make next-to-leading order symmetry breaking predictions for two linear combinations of axial charges.