On the Positronium g-factor

TL;DR

This paper discusses the significance of the positronium g-factor, its current experimental value, and its potential role in resolving discrepancies between quantum electrodynamics predictions and experimental results on positronium hyperfine splitting.

Contribution

It highlights the importance of accurately considering the positronium g-factor and provides the only existing experimental measurement of it.

Findings

Experimental g-factor value: 2.0023 ± 0.0012 at 3σ

Positronium g-factor impacts hyperfine splitting analysis

Potential to resolve QED-experiment discrepancies

Abstract

In this letter, we recall the main facts concerning the g-factor of positronium and we show how the value of the g-factor of the positronium is important. Taking it better into consideration may provide a solution to the reported discrepancy between QED theory and experiments concerning the hyperfine splitting of the fundamental level of the positronium. We also give the only experimental value that existing experiments can provide, $g_{\mathrm{Ps}}=2.0023\pm 0.0012$ at $3\sigma$.