Production of Leptonic Bound States in Electron–Positron Annihilation

We study the production of single dimuonium and ditauonium in electron–positron annihilation in quantum electrodynamics. Two mechanisms of one- and two-photon electron–positron annihilation are taken into account when calculating the amplitudes and cross-sections of leptonia production. We take into account relativistic corrections in the production amplitude connected with the relative momenta of leptons and with the transformation law of the bound state wave function from the rest frame to the moving reference frame.