Parity-Violating M{\o}ller Scattering at NNLO: Closed Fermion Loops

TL;DR

This paper presents a comprehensive calculation of two-loop fermion loop corrections to polarized Møller scattering asymmetry, crucial for precise measurements in upcoming experiments, and estimates the total two-loop effects.

Contribution

It provides the first complete gauge-invariant two-loop fermion loop correction calculation for Møller scattering asymmetry, enhancing theoretical precision.

Findings

Two-loop fermion loop corrections are about 1.3% of the tree-level asymmetry.

The corrections involving two and one closed fermion loops are numerically similar to one-loop bosonic corrections.

Estimated remaining two-loop contributions are discussed for future experimental implications.

Abstract

A complete, gauge-invariant computation of two loop virtual corrections involving closed fermion loops to the polarized M{\o}ller scattering asymmetry is presented. The set of contributions involving two closed fermion loops and the set involving one closed fermion loop are numerically similar in magnitude to the one-loop bosonic corrections and yield an overall correction of 1.3% relative to the tree-level asymmetry. We estimate sizes of remaining two-loop contributions and discuss implications for the upcoming MOLLER experiment.