Massive three-loop form factors: anomaly contribution

TL;DR

This paper calculates three-loop corrections to massive quark form factors, focusing on anomaly contributions and verifying chiral Ward identities, providing precise results across all energy ranges.

Contribution

It introduces a semi-analytic method for three-loop calculations and thoroughly analyzes anomaly and pseudoscalar contributions in massive quark form factors.

Findings

Explicit three-loop form factor results across energy ranges

Verification of chiral Ward identity at three-loop order

Detailed analysis of anomaly and pseudoscalar contributions

Abstract

We compute three-loop corrections to the singlet form factors for massive quarks using a semi-analytic method which provides precise results over the whole kinematic range. Particular emphasis is put on the anomaly contribution originating from an external axial-vector current. We also discuss in detail the contribution for a pseudoscalar current and verify the chiral Ward identity to three-loop order. Explicit results are presented for the low- and high-energy regions and the expansions around threshold.