Holographic estimate of the meson cloud contribution to nucleon axial form factor

TL;DR

This paper employs light-front holography to quantify the valence quark and meson cloud contributions to the nucleon axial form factor, aligning well with lattice QCD data and providing new insights into the meson cloud's role.

Contribution

It introduces a holographic model that estimates meson cloud effects on the nucleon axial form factor, incorporating empirical data and lattice QCD insights.

Findings

Good agreement with empirical data when including ~30% meson cloud

Valence quark contribution aligns with lattice QCD at small pion masses

Meson cloud contribution decreases more slowly with momentum transfer than in quark models

Abstract

We use light-front Holography to estimate the valence quark and the meson cloud contributions to the nucleon axial form factor. The free couplings of the holographic model are determined by the empirical data and by the information extracted from lattice QCD. The holographic model provides a good description of the empirical data when we consider a meson cloud mixture of about 30\% in the physical nucleon state. The estimate of the valence quark contribution to the nucleon axial form factor compares well with the lattice QCD data for small pion masses. Our estimate of the meson cloud contribution to the nucleon axial form factor has a slower falloff with the square momentum transfer compared to typical estimates from quark models with meson cloud dressing.