Details on the ${\cal{O}}(m_e \alpha^6)$ Positronium Hyperfine Splitting due to Single Photon Annihilation

TL;DR

This paper provides a detailed analytic calculation of the single-photon annihilation contributions to positronium hyperfine splitting at order $m_eeta^6$, advancing the theoretical understanding within non-relativistic effective theories.

Contribution

It offers the first comprehensive analytic derivation of the $m_eeta^6$ order contributions from single-photon annihilation in positronium hyperfine splitting.

Findings

Analytic expressions for single-photon annihilation contributions derived.

Enhanced understanding of positronium hyperfine splitting at high precision.

Review of current theoretical status of positronium ground state.

Abstract

A detailed presentation is given of the analytic calculation of the single-photon annihilation contributions to the positronium ground state hyperfine splitting to order $m_e\alpha^6$ in the framework of non-relativistic effective theories. The current status of the theoretical description of the positronium ground state hyperfine splitting is reviewed.