11 citations · 21 across the 7 of their papers we have counts for
7 papers
On the spectra of atoms and hadrons
Hartmut Pilkuhn
For relativistic closed systems, an operator is explained which has as stationary eigenvalues the squares of the total cms energies, while the wave function has only half as many c…
-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…
Hyperfine interactions between electrons
R. Haeckl, H. Pilkuhn
The relativistic Breit Hamiltonian between electrons is transformed into an effective vector potential for the th electron, having the structure of a re…