Eight-component two-fermion equations

Abstract

An eight-component formalism is proposed for the relativistic two-fermion problem. In QED, it extends the applicability of the Dirac equation with hyperfine interaction to the positronium case. The use of exact relativistic two-body kinematics entails a CP-invariant spectrum which is symmetric in the total cms energy. It allows the extension of recent α^6 recoil corrections to the positronium case, and implies new recoil corrections to the fine and hyperfine structures and to the Bethe logarithm.

Revtex, accepted for publication in Phys. Rev. A

References in corpus (2)

• The Single Photon Annihilation Contributions to the Positronium Hyperfine Splitting to Order $m_e{\alpha }^6$
• NRQED and Next-to-Leading Hyperfine Splitting in Positronium

Cited by in corpus (2)

• $\mathcal{C}\mathcal{P}\mathcal{T}$-invariant two-fermion Dirac equation with extended hyperfine operator
• Two fermion relativistic bound states