Systematic effects in the search for the muon electric dipole moment using the frozen-spin technique

TL;DR

This paper develops a quantitative framework to analyze and validate systematic effects that could mimic the muon EDM signal in a high-precision frozen-spin experiment, aiming to improve measurement accuracy.

Contribution

It provides analytical equations and simulation validation for systematic effects in the frozen-spin muon EDM search method.

Findings

Validated equations for muon spin motion in electromagnetic fields

Quantitative analysis of systematic effects in the frozen-spin technique

Guidelines for minimizing false EDM signals

Abstract

At the Paul Scherrer Institute (PSI) we are developing a high precision instrument to measure the muon electric dipole moment (EDM). The experiment is based on the frozen-spin method in which the spin precession induced by the anomalous magnetic moment is suppressed, thus increasing the signal-to-noise ratio for EDM signals to achieve a sensitivity otherwise unattainable using conventional $g-2$ muon storage rings. The expected statistical sensitivity for the EDM after a year of data taking is $6\times 10^{-23} e\cdot$cm with the $p = 125$ MeV/c muon beam available at the PSI. Reaching this goal necessitates a comprehensive analysis on spurious effects that mimic the EDM signal. This work discusses a quantitative approach to study systematic effects for the frozen-spin method when searching for the muon EDM. Equations for the motion of the muon spin in the electromagnetic fields of the experimental system are analytically derived and validated by simulation.