Orateur
Description
In this talk I report our recent progress on solving the postronium system in a basis light-front Hamiltonian approach with the light-front QED Hamiltonian as input. Both the leading Fock sector ($|e^+e^-\rangle$) and the higher sector containing one dynamical photon ($|e^+e^-\gamma\rangle$) are included in the basis. We found that the rotation symmetry of the positronium system provides natural cutoffs in momentum space for the particles in the basis. We performed the calculation at the physical electromagnetic coupling. We obtained the mass spectrum and charge radii of the low-lying states which reasonably agree with the results from non-relativistic quantum mechanics. The subleading helicity components of the postronium states naturally appear due to relativistic effects. Finally I will report the photon distribution in the positronium states.
