Bound States in Quantum Field Theory
Phys. Rev. 84, 350 – Published 15 October, 1951
DOI: https://doi.org/10.1103/PhysRev.84.350
Abstract
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 the states of the system. These wave functions depend exponentially on the energies of the states to which they correspond and therefore provide a means of calculating energy levels of bound states.