High-precision measurement of the atomic mass of the electron

TL;DR

This paper reports a highly precise measurement of the electron's atomic mass, achieved by combining experimental magnetic moment data with advanced quantum electrodynamics calculations, surpassing previous standards and enabling future fundamental physics research.

Contribution

It introduces a novel combination of experimental and theoretical methods to significantly improve the precision of the electron mass measurement.

Findings

Atomic mass of the electron is measured with 13 times higher precision than previous values.

The result enhances the foundation for future tests of the Standard Model.

The method integrates precise magnetic moment measurements with bound-state QED calculations.

Abstract

The quest for the value of the electron's atomic mass has been subject of continuing efforts over the last decades. Among the seemingly fundamental constants which parameterize the Standard Model (SM) of physics and which are thus responsible for its predictive power, the electron mass me plays a prominent role, as it is responsible for the structure and properties of atoms and molecules. This manifests in the close link with other fundamental constants, such as the Rydberg constant and the fine-structure constant {\alpha}. However, the low mass of the electron considerably complicates its precise determination. In this work we present a substantial improvement by combining a very accurate measurement of the magnetic moment of a single electron bound to a carbon nucleus with a state-of-the-art calculation in the framework of bound-state Quantum Electrodynamics. The achieved precision of the atomic mass of the electron surpasses the current CODATA value by a factor of 13. Accordingly, the result presented in this letter lays the foundation for future fundamental physics experiments and precision tests of the SM.