Anomalous states of positronium

Chris W. Patterson
2019 Physical Review A  
The energies and wave functions of the two-body Dirac equation for positronium are compared with those of the Pauli approximation and the Bethe-Salpeter equation. The unusual behavior of the ground-state wave function of the Dirac equation is explained in terms of anomalous bound-state solutions.
doi:10.1103/physreva.100.062128 fatcat:fe4dwajx3nf5binil43ibl7fiq