One More Hard Three-Loop Correction to Parapositronium Energy Levels

Abstract

A hard three-loop correction to parapositronium energy levels of order $m{\alpha }^7$ is calculated. This nonlogarithmic contribution is due to the insertions of one-loop photon propagator in the fermion lines in the diagrams with virtual two-photon annihilation. We obtained $\Delta E=0.03297(2)(m{\alpha }^7/{\pi }^3)$ for this energy shift.

Version to be published in Phys. Rev.D, results unchanged

References in corpus (3)

• Positronium energy levels at order $m{\alpha }^7$: light-by-light scattering in the two-photon-annihilation channel
• Hard Nonlogarithmic Corrections of Order $m{\alpha }^7$ to Hyperfine Splitting in Positronium
• Radiative-Recoil Corrections to Hyperfine Splitting: Polarization Insertions in the Muon Factor

Cited by in corpus (1)

• $P-$state Positronium for Precision Physics: an Ultrafine Splitting at ${\alpha }^6$