Coulomb energy in QCD

We discuss the profiles of the longitudinal chromo-electric field generated by static quark-antiquark, QQ¯ pair. Using a variational ansatz for the ground state we show that a flux tube-like structure emerges. This structure, however is different from, for example the full action density. This is because the Coulomb potential itself is different from the energy of the sources computed from the expectation value of the Wilson loop.