Polarimetry for measuring the vacuum magnetic birefringence with quasi-static fields: a systematics study for the VMB@CERN experiment

TL;DR

This paper investigates the systematic errors in a polarimetric method for measuring vacuum magnetic birefringence, identifying a key systematic effect and proposing solutions to improve measurement accuracy in the VMB@CERN experiment.

Contribution

It provides a detailed analysis of systematic effects in polarimetric measurements of vacuum magnetic birefringence and suggests practical workarounds for experimental implementation.

Findings

Identified a systematic effect at the same frequency as the signal

Characterized the origin of the systematic effect

Proposed a viable workaround to mitigate the systematic error

Abstract

We present an experimental systematics study of the polarimetric method for measuring the vacuum magnetic birefringence based on a pair of rotating half-wave plates. The presence of a systematic effect at the same frequency as the sought for magneto-optical effect inhibits the use of strictly constant magnetic fields. We characterise this systematic, discuss its origin and propose a viable workaround.