We propose a new relativistic two-body formalism which reduces to a nonrelativistic
Schrödinger theory for a single effective particle. The formalism is equal in rigor to that of …

This work advocates the use in atomic physics of a new relativistic two-body formalism equal
in rigor to the Bethe-Salpeter formalism and clearly superior to it in several respects …

We study an approach to the relativistic two-body problem that represents a considerable
improvement of the Bethe-Salpeter equation. The main advantages are the improved …

A method is described of solving Bethe-Salpeter equations for spin-½ particles using a
standard quasipotential approximation with a correction series. A three-dimensional, 16 …

Abstract The Bethe-Salpeter (BS) equation for a spin-1 2 fermion-antifermion bound system
is considered for the case in which the kernel is static and is the fourth component (ie, three …

We propose a Coulomb-like kernel for the relativistic two-fermion Bethe-Salpeter equation,
to be used as the lowest-order approximation in systematic perturbative calculation of bound …

The relativistic two-body equation of Bethe and Salpeter is derived from field theory. It is
shown that the Feynman two-body kernel may be written as a sum of wave functions over …

Abstract The Bethe-Salpeter equation for spin-1 2 particles is analyzed by the use of helicity
amplitudes. Decomposition into partial-wave amplitudes reduces the equation into three …

We compute O (α 3 ln α) relative corrections to the ground-state hyperfine splitting of a QED
two-body bound state with different masses of constituents. The general result is then …

Muonium and positronium potentials with radiative corrections are derived from the
scattering operator, and general results for the spectra of these systems to order α 3 R∞ are …