Two-body Dirac equation: illustration in one space dimension

Various features that are characteristic of the two-body Dirac equation but not of the one-body Dirac equation are illustrated by means of solvable examples (mainly square-well potentials) in one space dimension. For the Lorentz character of the potential there are three types; vector, scalar, and pseudoscalar. We classify the bound-state solutions as normal and abnormal. As the interaction is adiabatically switched off, the energy of the …