The three-loop singlet contribution to the massless axial-vector quark form factor

TL;DR

This paper calculates three-loop pure-singlet corrections to the massless quark axial-vector form factor in QCD, addressing UV renormalization and infrared singularities with the Larin prescription.

Contribution

It provides the first three-loop computation of the pure-singlet axial-vector form factor in massless QCD, including UV renormalization and infrared structure analysis.

Findings

Computed three-loop pure-singlet axial-vector form factor

Analyzed UV renormalization using Larin prescription

Explained infrared singularity structure and finite remainder

Abstract

We compute the three-loop corrections to the quark axial vector form factor in massless QCD, focusing on the pure-singlet contributions where the axial vector current couples to a closed quark loop. Employing the Larin prescription for $\gamma_5$, we discuss the UV renormalization of the form factor. The infrared singularity structure of the resulting singlet axial-vector form factor is explained from infrared factorization, defining a finite remainder function.