Positronium Spectroscopy in a Magnetic Field

TL;DR

This paper analyzes hyperfine positronium spectroscopy in magnetic fields with arbitrary orientation and electron polarization, enhancing the understanding for high-sensitivity positron polarimeters in beta decay experiments.

Contribution

It generalizes previous models by considering non-parallel magnetic fields and electron polarization in positronium spectroscopy analysis.

Findings

Derived new theoretical framework for positronium in arbitrary magnetic fields

Applicable to high-sensitivity positron polarimeters in beta decay

Improves accuracy of positronium spectral measurements

Abstract

Hyperfine spectroscopy of positronium formed in the presence of a static magnetic field is considered. Generalising the situation hitherto developed in the literature, the magnetic field is not assumed to be parallel to the momentum of incoming polarised positrons, while the possibility of electron polarisation is also included in the analysis. The results are of application to high sensitivity positron polarimeters used in current $\beta$ decay experiments.