Parity-Violating Moller Scattering at Next-to-Next-to-Leading Order: Closed Fermion Loops

A complete, gauge-invariant computation of two-loop virtual corrections involving closed fermion loops to the polarized Moller 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 the remaining two-loop contributions and discuss implications for the upcoming MOLLER (Measurement of a Lepton-Lepton Electroweak Reaction) experiment.

Automated summary

This study presents a complete, gauge-invariant computation of two-loop virtual corrections involving closed fermion loops to the polarized Moller scattering asymmetry. The contributions from two closed fermion loops and one closed fermion loop are numerically similar in magnitude to the one-loop bosonic corrections, resulting in an overall correction of 1.3% relative to the tree level asymmetry. The authors estimate the sizes of the remaining two-loop contributions and discuss implications for the upcoming MOLLER experiment.