11 citations · 21 across the 5 of their papers we have counts for
5 papers
-invariant two-fermion Dirac equation with extended hyperfine operator
Viktor Hund, Hartmut Pilkuhn
For the S-states of muonium and positronium, the hyperfine shifts to the order of a recently derived two-fermion equation with explicit -invariance are checked agai…
Non-perturbative energy levels of two-fermion bound states
Viktor Hund, Hartmut Pilkuhn
For the S-states of positronium and muonium, the terms of an expansion of energy levels in powers of the fine structure constant are also members of a "recoil series". The firs…
Eight-component two-fermion equations
Ruth Haeckl, Viktor Hund, Hartmut Pilkuhn
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 posi…
Eight-component differential equation for leptonium
R. Haeckl, V. Hund, H. Pilkuhn
It is shown that the potential for lepton-antilepton bound states (leptonium) is the Fourier transform of the first Born approximation to the QED scattering amplitude in an 8-compo…
Binary Boosts
R. Haeckl, V. Hund, H. Pilkuhn
The relativistic motion of an isolated two--body system (bound or unbound) of given lab energy in QED is separated into cms motion and relative motion. The relative motion…