The nucleon's octet axial-charge g_A^8 with chiral corrections

TL;DR

This paper investigates the nucleon's octet axial-charge g_A^8 using the Cloudy Bag model, revealing a significant reduction from the traditional value, which impacts the interpretation of deep inelastic scattering data.

Contribution

It introduces a chiral correction-based calculation of g_A^8 that challenges the standard SU(3) symmetry assumption in hyperon beta-decay analyses.

Findings

g_A^8 is reduced by up to 20% from the traditional value

The reduction increases the flavor singlet axial charge g_A^0|_inv

The difference between g_A^0|_inv and g_A^8 is significantly decreased

Abstract

The value of the nucleon's flavour-singlet axial-charge extracted from polarised deep inelastic scattering is sensitive to the value of the octet axial-charge g_A^8 which is usually taken from an analysis of hyperon beta-decays within the framework of SU(3) symmetry, namely 0.58 \pm 0.03. Using the Cloudy Bag model we find that the value of g_A^8 is reduced by as much as 20% below the usual phenomenological value. This increases the value of the flavour singlet axial charge (g_A^0|_inv) derived from deep inelastic data and significantly reduces the difference between it and g_A^8.