Fully Relativistic Quark Models for Heavy-Light Systems
  A fully relativistic quark model is constructed and applied to the study of wave-functions as well as the spectrum of heavy-light mesons. The free parameters of the model are a constituent quark mass and (on the lattice) an adjustable r-parameter in the fermionic kinetic energy, while the confinement is introduced via potentials measured by MonteCarlo. The results are compared to Monte Carlo energies and Coulomb-gauge wave functions. They are in very good agreement with the data. A comparison with previous models suggests that we are seeing in the Monte Carlo data the quantum-relativistic delocalization of the quark due to Zitterbewegung. 
S. A. Pernice