Two-loop massive fermionic operator matrix elements and intial state QED corrections to e^+e^- \to \gamma^*/Z^*

TL;DR

This paper calculates two-loop massive operator matrix elements for fermions to improve precision in initial state QED corrections for electron-positron annihilation into neutral gauge bosons, using renormalization group methods.

Contribution

It introduces a calculation of two-loop massive operator matrix elements for external fermions, advancing the accuracy of QED radiative corrections in electron-positron collisions.

Findings

Provides two-loop operator matrix elements for massive fermions.

Enables more precise initial state radiative correction calculations.

Uses renormalization group techniques for the computation.

Abstract

We describe the calculation of the two--loop massive operator matrix elements for massive external fermions. These matrix elements are needed for the calculation of the $O(\alpha^2)$ initial state radiative corrections to $e^+e^-$ annihilation into a neutral virtual gauge boson, based on the renormalization group technique.