Lepton bound states in a fundamental description of elementary forces
  In the flavour dependence hadrons and leptons show a mass relation, not expected in the Standard Model. This can be understood in an analysis, based on a particle Lagrangian with Maxwell term, boson-boson coupling and massless fermions (quantons), in which hadrons are described as stationary systems of quantons bound by an electric interaction, whereas leptons represent systems bound magnetically. 
Hans-Peter Morsch
physics.gen-ph