Three-loop massive form factors: complete light-fermion and large-$N_c$ corrections for vector, axial-vector, scalar and pseudo-scalar currents

TL;DR

This paper calculates three-loop quantum chromodynamics (QCD) corrections to massive quark form factors for various currents, including all light-fermion effects and large-$N_c$ approximations for non-fermionic parts, advancing precision in theoretical predictions.

Contribution

It provides the first complete three-loop corrections to massive quark form factors with light-fermion and large-$N_c$ approximations, covering vector, axial-vector, scalar, and pseudo-scalar currents.

Findings

All light-fermion loop corrections included.

Non-fermionic corrections computed in large-$N_c$ limit.

Results enhance precision of QCD form factor calculations.

Abstract

We compute the three-loop QCD corrections to the massive quark form factors with external vector, axial-vector, scalar and pseudo-scalar currents. All corrections with closed loops of massless fermions are included. The non-fermionic part is computed in the large-$N_c$ limit, where only planar Feynman diagrams contribute.